Unidentified
snipers have opened fire on a convoy of UN experts investigating
suspected chemical weapons attacks in Syria's capital, the UN has said.
One car was shot at "multiple times", forcing the convoy to turn back.
Syrian state media blamed opposition "terrorists" for the attack, though the claim could not be verified.
The UN team later resumed its mission, entering the western
district of Muadhamiya to gather evidence, before returning to central
Damascus.
Hundreds died in alleged attacks on Wednesday in five districts near Damascus.
The US said there was little doubt that Syrian forces used
chemical weapons in the attacks, which reportedly killed more than 300
people in rebel-held areas.
Syrian President Bashar al-Assad dismissed the accusation as
"an insult to common sense" and warned the US against military
intervention.
"If someone is dreaming of making Syria a puppet of the West,
then this will not happen," he told the Russian newspaper Izvestiya.
'Intimidation'
The 20-member UN inspection team has been in Syria since 18
August to look into three earlier suspected chemical attacks. They were
given permission on Sunday to examine the Damascus locations.
The UN inspectors have been talking to doctors in Muadhamiya
The experts intend to take soil, blood, urine and tissue
samples for laboratory testing but they are unlikely to apportion blame
for any of the attacks.
Video footage posted online appears to show UN inspectors in Muadhamiya taking samples and talking to residents.
They went to a Red Crescent centre and spoke to doctors, opposition activists said.
On the video, which the BBC has not been able to fully
authenticate, one resident is heard telling an inspector of heavy raids
on the district, with "over 600 canister strikes...12 tanks, 100
soldiers".
Shortly after setting out from their hotel in Damascus, the
inspectors' cars came under fire "multiple times by unidentified
snipers", according to a statement from the UN.
Continue reading the main story
Analysis
Frank Gardner
BBC security correspondent
Whitehall officials say no firm decision is likely to be taken
on how Britain will respond to last week's alleged chemical attack in
Syria until at least Wednesday.
That is when UK PM David Cameron will be chairing a session
of the National Security Council, attended by military and intelligence
chiefs and senior ministers.
It follows intense consultations between London and
Washington with Downing Street keen to stress the two countries are
acting in concert.
Any military response, if it is decided on, is most likely to
be confined to a one-off or limited guided missile strikes on selected
Syrian military targets using Tomahawk cruise missiles fired from US
Navy warships stationed hundreds of miles away in the eastern
Mediterranean.
US vessels there are reported to have around 400 such
missiles onboard, while a Royal Navy submarine in the region can also
carry cruise missiles.
But Russia, Syria and Iran have all issued strong warnings against any western military action.
The team returned safely back to the government checkpoint before setting out again.
The convoy was "deliberately targeted" and it seemed someone
was trying to intimidate the team, the UN Secretary General's spokesman,
Farhan Haq, told the BBC.
The inspectors have now returned to their hotel and are expected to resume their work on Tuesday.
Military action
A year ago, US President Barack Obama said the use of chemical
weapons by the Syrian government would be "a red line" that could
trigger US military action.
Washington has recently bolstered its naval presence in the
eastern Mediterranean, and military leaders from the US, UK and their
allies are meeting in Jordan.
But the UN Security Council remains divided, with China and
Russia appearing unlikely to drop their objection to stricter sanctions
on Mr Assad's government.
Chinese Foreign Minister Wang Yi said on Monday that
diplomats should be cautious in dealing with the chemical weapons issue,
and Moscow warned Western nations not to prejudge the outcome of the
inspections.
Western politicians have begun to suggest taking action outside of the UN system.
UK Foreign Secretary William Hague told the BBC that action
could be taken without UN approval if there was "great humanitarian
need" in Syria.
His French counterpart Laurent Fabius suggested the UN Security Council could be bypassed "in certain circumstances".
But in his latest comments on the crisis, Russian Foreign
Minister Sergei Lavrov said any intervention in Syria without a UN
mandate would be a "grave violation of international law".
The West, he told a news conference in Moscow, had not been
able to come up with any proof of chemical weapons use while "saying at
the same time that the red line has been crossed and there can be no
delay".
'Neurotoxic symptoms'
Western officials were unimpressed with Syria's decision to allow in the UN experts.
Mr Hague said evidence could have been tampered with, degraded or destroyed in the five days since the attack.
A senior White House official, quoted by AP news agency, dismissed the visit as "too late to be credible".
Medecins Sans Frontieres (MSF) said on Saturday that three
hospitals it supports in the Damascus area had treated about 3,600
patients with "neurotoxic symptoms" on Wednesday morning, of whom 355
had died.
While MSF said it could not "scientifically confirm" the use
of chemical weapons, staff at the hospitals described a large number of
patients arriving in the space of less than three hours with symptoms
including convulsions, pinpoint pupils and breathing problems.
Syria's security forces are widely believed to possess large undeclared stockpiles of mustard gas and sarin nerve agent.
It is one of seven countries that have not joined the 1997 convention banning chemical weapons.
