UN inspectors leave Syria as US weighs 'limited act'
UN inspectors investigating the alleged use of chemical weapons in Syria have left Damascus.
They crossed into neighbouring Lebanon just hours after President Barack Obama said the US was considering a "limited narrow act" against Syria.
Citing a US intelligence assessment, Secretary of State John Kerry accused Syria of using chemical weapons to kill 1,429 people, including 426 children.
Syria said the US claim was "full of lies", blaming rebels for the attacks.
The UN inspectors - investigating what happened in the Damascus suburbs on 21 August - left their hotel in the Syrian capital in a convoy of vehicles on Saturday morning and later arrived in Lebanon.
During their visit, they carried out four days of inspections.
It could be two weeks before their final report is ready, UN Secretary General Ban Ki-moon has told diplomats.
Their departure from Syria removes both a practical and a political obstacle to the launch of American-led military action, the BBC's Kevin Connolly in Beirut reports.
Any attack that might have placed them in danger was unthinkable and would have seemed premature before their work on the ground was complete, our correspondent adds.
Russia - a key ally of Syria - has warned that "any unilateral military action bypassing the UN Security Council" would be a "direct violation of international law".
Syrian President Bashar al-Assad has said his country will defend itself against any Western "aggression". French President Francois Hollande has reaffirmed his support for the US stance.
Speaking on Friday, President Obama said the alleged attack in Damascus' suburbs on 21 August was "a challenge to the world" that threatened America's "national security interests".
"We cannot accept a world where women and children and innocent civilians are gassed on a terrible scale.
"The world has an obligation to make sure that we maintain the norm against the use of chemical weapons."
But the US leader stressed that Washington was "looking at the possibility of a limited, narrow act", and there would be "no boots on the ground" or "long-term campaign".
Mr Obama comments came shortly after Secretary of State John Kerry laid out a raft of what Washington said was a "high confidence" intelligence assessment about the attack.
The main findings of the released unclassified summary state that:
- the attack killed 1,429 people, including 426 children
- Syrian military chemical weapons personnel were operating in the area in the three days before the attack
- Satellite evidence shows rockets launched from government-held areas 90 minutes before first report of chemical attack
- 100 videos attributed to the attack show symptoms consistent with exposure to nerve agent
- Communications were intercepted involving a senior Damascus official who "confirmed chemical weapons were used" and was concerned about UN inspectors obtaining evidence
The US said its assessment was backed by accounts from medical personnel, witnesses, journalists, videos and thousands of social media reports.
Mr Kerry said the US already had the facts, and nothing that the UN inspectors found could tell the world anything new.
He also described Mr Assad as "a thug and a murderer".
In response, Syria's state-run news agency Sana said Mr Kerry was using "material based on old stories which were published by terrorists over a week ago".
The UN Security Council is unlikely to approve any military intervention because of opposition from Russia - one of the five permanent members.
Moscow, along with China, has vetoed two previous draft resolutions on Syria.
The US was also dealt a blow on Thursday when the UK parliament rejected a motion supporting the principle of military intervention.
The vote rules the UK out of any potential military alliance.
British Prime Minister David Cameron and Mr Obama spoke over the telephone on Friday, agreeing to continue to co-operate on international issues.
The president told Mr Cameron he "fully respected" the approach taken by the UK government.
US officials said they would continue to push for a coalition, and France said it was ready to take action in Syria alongside the US.
Mr Obama and French President Francois Hollande discussed the issue in a telephone conversation on Friday, Paris said.
It said that both leaders wanted to send Damascus a "strong message" to condemn the alleged use of chemical weapons.
Neither France nor the US needs parliamentary approval for military action.
Another US ally, Turkey, called for action similar to the Nato bombing raids in the former Yugoslavia in 1999.
Nato carried out 70 days of air strikes to protect civilians from attack in Kosovo, despite not having a UN resolution.
Turkish Prime Minister Recep Tayyip Erdogan also said that any military intervention should be aimed at toppling Mr Assad.
The use of chemical weapons is banned under several treaties, and considered illegal under customary international humanitarian law.
The Syrian army is known to have stockpiles of sarin and other chemical agents.
Earlier accounts of the attack in Damascus quoted officials from medical charity Medecins Sans Frontieres as saying 355 people had been killed.
The UN inspectors have collected various samples that will now be examined in laboratories across the world.
The UN team is not mandated to apportion blame for the attacks.
More than 100,000 people are estimated to have died since the conflict erupted in Syria in March 2011, and the conflict has produced at least 1.7 million refugees.
Forces which could be used against Syria:
•Four US destroyers - USS Gravely, USS Ramage, USS Barry and USS Mahan - are in the eastern Mediterranean, equipped with cruise missiles. The missiles can also be fired from submarines, but the US Navy does not reveal their locations
•Airbases at Incirlik and Izmir in Turkey, and in Jordan, could be used to carry out strikes
•Two aircraft carriers - USS Nimitz and USS Harry S Truman are in the wider region
•French aircraft carrier Charles de Gaulle is currently in Toulon in the western Mediterranean
•French Raffale and Mirage aircraft can also operate from Al-Dhahra airbase in the UAE