Fear of a dramatic escalation in the two-and-a-half-year conflict prompted some 6,000 Syrians to flee into Lebanon over a 24-hour period, or more than six times the average daily flow.
A jittery Israel ordered a special call-up of reserve troops Wednesday as residents lined up at gas-mask distribution centers, preparing for possible hostilities with Syria.
A week after the purported chemical attack on rebel-held areas outside Damascus, momentum has been building for a possible strike by the U.S. and its allies against the regime of Syrian President Bashar Assad.
U.N. Secretary General Ban Ki-moon however said that no action should be taken until the U.N. chemical weapons inspectors finish their investigation.
"Let them conclude ... their work for four days and then we will have to analyze scientifically" their findings and send a report to the U.N. Security Council, he said Wednesday from The Hague. The U.N. said the analysis would be done "as quickly as possible."
At the same time, Syria's main allies Russia and Iran warned of dire consequences for the region if a military intervention is launched.
U.S. leaders, including Vice President Joe Biden, have charged that Assad's government fired deadly chemical weapons near Damascus last week that, according to the group Doctors Without Borders, have killed 355 people.
Syria, which sits on one of the world's largest stockpiles of chemical weapons, has denied the charges.
The U.S. has not presented concrete proof of Syrian regime involvement in an alleged chemical weapons attack, and U.N. inspectors have not endorsed the allegations — though the U.N. envoy to Syria, Lakhdar Brahimi, said Wednesday that evidence suggests some kind of "substance" was used that killed hundreds on Aug. 21.
On Wednesday, the U.N. inspectors visited the eastern Damascus suburbs of Mleeha and Zamalka, activists said. Amateur video showed a convoy of five cars with U.N. markings, followed by armed rebels in pickups.
The video showed the inspectors visiting a clinic and interviewing a man through a translator. Two inspectors were present as a nurse drew blood from a man lying on an exam table. One of the experts is heard in the video saying he and his team members have collected blood, urine and hair samples.
The videos appeared consistent with other AP reporting, including Skype interviews with anti-regime activists.
One activist said the team took hair and skin samples of five suspected victims in Zamalka during a 90-minute visit. He spoke on condition of anonymity for fear of regime reprisals.
The U.N. team in Syria did not issue a statement about Wednesday's trip.
The U.N.'s Ban, meanwhile, pleaded for more time to give diplomacy another chance to end the conflict that has killed more than 100,000 people.
Marking the centenary of a venue for peaceful conflict resolution, he said: "Here in the Peace Palace, let us say: Give peace a chance. Give diplomacy a chance. Stop fighting and start talking."
Britain was to turn to the Security Council later Wednesday, with a resolution seeking to condemn the Syrian government for the alleged attack. Britain would seek backing for "necessary measures to protect civilians" in Syria under Chapter 7 of the U.N. charter, the office of Prime Minister David Cameron said. Military force is one of the options that can be authorized, but that possibility faces a likely veto from Assad-ally Russia.
A French diplomatic official said the British resolution has virtually no chance of passing, but is being introduced to show that all diplomatic steps were being exhausted. He spoke on condition of anonymity because he was not allowed to disclose details of the deliberations.
Ban said the Security Council, whose permanent members are bitterly divided over Syria, must not go "missing in action."
The growing fear of escalation sent wider ripples across the region.
Lebanese security officials in the country's Bekaa Valley near the border with Syria said at least 6,000 Syrians have crossed into Lebanon in the past 24 hours through the main Masnaa border crossing, including an estimated 4,000 on Wednesday.
The normal daily rate is 500 to 1,000 Syrian refugees coming to Lebanon, depending on the level of fighting.
Witnesses said they saw long lines of cars packed with families and belongings at the crossing. There was also traffic in the other direction — a security official said around 2,000 crossed into Syria on Wednesday — but many of them said they were going in to evacuate relatives from Syria.
Um Ahmad, 45, crossed to Lebanon with her five children Wednesday, fearing U.S. strikes on Damascus.
"Isn't it enough, all the violence and fighting that we already have in the country, now America wants to bomb us, too?" she said, declining to give her full name for security concerns.
Her husband said they have no one in Lebanon but came anyway because of their children. "What will we do here, where will we go? I don't know — but hopefully we'll be safe."
Nearly 2 million Syrians have fled their country since the crisis began in March 2011, and millions more are displaced inside Syria.
In Israel, the government ordered a "limited" call-up of reserve units to beef up civil defense preparations and to operate air-defense units near the border. Officials said the call-up is anticipated to bring in "hundreds" of troops.
Israel fears that Syria may respond by attacking the Jewish state, a close American ally. While Israeli officials believe the chances of a Syrian strike remain slim, people were clearly preparing for the possibility.
Large crowds lined up at gas-mask distribution centers. Maya Avishai of the Israeli postal service, which oversees gas mask distribution, said demand has tripled in recent days. About five million Israelis, roughly 60 percent of the population, now have gas masks, she said.
Jordan, meanwhile, said it will not be used as a launching pad for attacks on Syria and the kingdom favors a diplomatic solution to the crisis. A U.S.-led strike would involve cruise missile attacks from the sea, which would not need to cross or make use of Jordanian territory.
But the remarks underline the U.S. ally's efforts to avoid further friction with its larger neighbor for fear that Assad or his Iranian backers could retaliate.
The remarks come a day after Jordan hosted a meeting of top commanders from Western and Middle Eastern countries, including some that are likely to participate in a military action.
"Jordan will not be a launching pad for any military action against Syria," said Information Minister Mohammad Momani.
NATO Secretary-General Anders Fogh Rasmussen said in a statement that any use of chemical weapons is unacceptable and a threat to international peace and security.
He stopped short, however, of squarely putting the responsibility on the Assad regime, citing only "information available from a wide variety of sources" as pointing to the Syrian regime as being behind the attack.
Two of Syria's staunchest backers, Iran and Russia, warned of dire consequences if the U.S. and its allies attack in Syria.
Such strikes "will lead to the long-term destabilization of the situation in the country and the region," said Russian Foreign Minister Sergey Lavrov.
Iranian Supreme Leader Ayatollah Ali Khamenei said Wednesday that attacking Syria would be catastrophic for the entire Middle East.
"Intervention of foreign and extra-regional powers in a country has no result other than sparking fire," Iran's state TV quoted Khamenei as saying. "Waging a war is like a spark in a gunpowder store ... its dimensions and consequences can't be predicted."
___ Laub reported from Beirut. Associated Press writers Yasmine Saker and Zeina Karam in Beirut, John Heilprin in Geneva, Jamal Halaby in Amman, Jordan, Mike Corder at The Hague, Daniel Estrin in Jerusalem, Juergen Baetz in Brussels, Gregory Katz in London and Jamey Keaten in Paris contributed reporting.
WASHINGTON (AP) — The Obama administration is laying the groundwork for potential military action in Syria in the coming days, with intelligence agencies readying additional evidence about last week's alleged chemical weapons attack and high-ranking U.S. officials declaring there was "no doubt" that Bashar Assad's government was to blame.
Administration officials also said Assad's actions posed a direct threat to U.S. national security, providing President Barack Obama with a potential legal justification for launching a strike without authorization from the United Nations or Congress. However, officials did not detail how the U.S. was directly threatened by an attack contained within Syria's borders. Nor did they present concrete proof that Assad was responsible.
"Allowing the use of chemical weapons on a significant scale to take place without a response would present a significant challenge to, threat to the United States' national security," White House spokesman Jay Carney said Tuesday.
The U.S. and international partners were unlikely to undertake military action before Thursday. That's when British Prime Minister David Cameron will convene an emergency meeting of Parliament, where lawmakers were expected to vote on a motion clearing the way for a British response.
Obama and Cameron spoke Tuesday, their second known conversation since the weekend. A Cameron spokesman said the two leaders agreed that a chemical attack had taken place, and that the Assad regime was responsible. Cameron "confirmed that the government had not yet taken a decision on the specific nature of our response, but that it would be legal and specific to the chemical weapons attack," the spokesman said.
Also Tuesday, Vice President Joe Biden became the highest-ranking U.S. official to charge that Assad's government fired chemical weapons last week near Damascus. Assad has denied using chemical weapons, calling the allegations "preposterous."
"There's no doubt who is responsible for this heinous use of chemical weapons in Syria: the Syrian regime," Biden said.
Obama is weighing a response focused narrowly on punishing Assad for violating international agreements that ban the use of chemical weapons, an act the president repeatedly has said would cross a "red line." Officials said the goal was not to drive the Syrian leader from power nor affect the broader trajectory of Syria's bloody civil war, which is now in its third year.
"The options we are considering are not about regime change," Carney told reporters.
According to U.S. officials, the most likely military operation would be largely sea-based, with the strikes coming primarily from Navy warships in the Mediterranean Sea. Fighter jets often are deployed to monitor the area and protect the ships, but Syria's robust air defense system makes airstrikes more difficult and risky.
Defense Secretary Chuck Hagel said military forces stood ready to strike Syria immediately if the commander in chief gave the order. The Navy has four destroyers in the eastern Mediterranean within range of targets inside Syria and also has warplanes in the region.
"We are ready to go," Hagel said in a BBC television interview Tuesday while traveling in Asia.
Ahead of any strike, the U.S. also planned to release additional intelligence it said would directly link Assad to the Aug. 21 attack in the Damascus suburbs. Syrian activists said hundreds of people were killed in the attack. A U.S. official said the intelligence report was expected to include "signals intelligence" — information gathered from intercepted communications.
All of the officials insisted on anonymity because they were not authorized to publicly discuss the internal deliberations.
Even before releasing that information, U.S. officials said they had very little doubt that Assad was culpable in the attack, based on witness reports, information on the number of victims and the symptoms of those killed or injured, and intelligence showing the Syrian government has not lost control of its chemical weapons stockpiles.
Other administration officials echoed Biden's comments, which marked a subtle shift in the administration's rhetoric on who bears responsibility for the attack. Earlier in the week officials would say only that there was "very little doubt" Assad was responsible.
BAGHDAD (AP) — Iraqi officials say a wave of bombings in Shiite Muslim areas in and around the capital Baghdad has left at least 51 people dead and wounded dozens.
Four police officers say Wednesday's attacks by explosives-laden cars, bombs and suicide bombers targeted parking lots, outdoor markets and restaurants in six of Baghdad's predominantly Shiite neighborhoods.
The areas hit included the neighborhoods of Kazimiyah, Sadr City, Shaab, Shula, Jamila and Mahmoudiyah.
Four medical officials confirmed the casualty figures. All officials spoke on condition of anonymity as they were not authorized to release information.
The attacks are part of a wave of killing that is the country's worst spate of bloodshed since 2008. More than 3,000 people have died in recent months.