UN inspectors reach Syria gas victims despite coming under fire
* Experts deliberately fired at by unidentified assailants-UN
* Russia says deeply concerned over possible US intervention
* Evidence has been destroyed, US and its allies say
* Western countries say strong response needed
* UN says Syria has agreed to ceasefire during inspections
UN chemical weapons inspectors in Syria met and took samples from victims of an apparent poison gas attack in a rebel-held suburb of Damascus today after the UN team themselves survived a gun attack on their convoy.
A Syrian doctor told Reuters from the town of Mouadamiya that investigators from the United Nations had crossed the frontline from the centre of the capital, which remains under the control of President Bashar al-Assad's forces. The U.N. said the shooting crippled one vehicle but mentioned no injuries.
With Western powers considering military strikes, despite vocal opposition from Assad and his Russian and Iranian allies, any evidence to support rebel claims that government forces fired gas-laden rockets five days ago that killed hundreds of civilians will be a key element in arguments for peace or war.
"I am with the team now," the doctor who uses the name Abu Karam told Reuters by telephone from rebel-held Mouadamiya.
"We are in the Rawda mosque and they are meeting with the wounded. Our medics and the inspectors are talking to the patients and taking samples from the victims now."
Another opposition activist said a large crowd was growing of people eager to air their grievances to the U.N. team. There was a plan for the experts also to take samples from corpses.
Syrian state television blamed rebel "terrorists" for the shooting, which briefly halted the convoy but failed to stop the inspectors from crossing the front line. The opposition blamed it on pro-Assad militiamen. Any delay diminishes whatever evidence the experts might recover.
With speculation mounting that NATO powers might fire cruise missiles to satisfy calls for action to protect Syrian civilians, U.S. Defense Secretary Chuck Hagel said any operation would be coordinated with allies. British Prime Minister David Cameron cut short a holiday to chair a top level security meeting.
"The United States is looking at all options regarding the situation in Syria. We're working with our allies and the international community," Hagel told a news conference.
"We are analysing the intelligence. And we will get the facts. And if there is any action taken, it will be in concert with the international community and within the framework of legal justification."
Hagel plans discussions with his British and French counterparts, a senior U.S. official said.
The French foreign minister said on Monday that Russian and Chinese vetoes in the U.N. Security Council may make it hard to get a U.N. agreement to satisfy international law. His British counterpart, however, said that should not prevent a response to the worst poison gas attack in 25 years.
The U.N. said in a statement that gunmen shot at the first vehicle in the team's six-car convoy, damaging it to the point that the team had to stop to find a replacement car.
"The first vehicle of the Chemical Weapons Investigation Team was deliberately shot at multiple times by unidentified snipers in the buffer zone area," it said. "It has to be stressed again that all sides need to extend their cooperation so that the team can safely carry out their important work."
Syria agreed on Sunday to let them visit the suspect sites. The United States and its allies say the offer came too late as evidence has probably been destroyed by heavy government shelling of the area since last Wednesday.
The team of chemical weapons experts wearing blue U.N. body armour left a Damascus hotel where they have been based for over a week, accompanied by a car of Syrian security personnel, as well as an ambulance. At least two mortar bombs struck the area of central Damascus on Monday.
Syrian state media said the mortar bombs were locally made and fired by "terrorists". SANA state news agency said three people were wounded.
Assad, who has been fighting a 2-1/2-year revolt, said accusations that his forces used chemical weapons were politically motivated and warned the United States against intervening in his country.
"Would any state use chemicals or any other weapons of mass destruction in a place where its own forces are concentrated? That would go against elementary logic. So accusations of this kind are entirely political," he told the Russian newspaper Izvestia in an interview.
"Failure awaits the United States as in all previous wars it has unleashed, starting with Vietnam and up to the present day."
The United Nations said Damascus agreed to a ceasefire while the U.N. experts are at the site for inspections.
Syria's conflict has so far been met with international deadlock. The growing violence has killed more than 100,000 people, stoked regional sectarian violence, and revived Cold War-era divisions between Western powers and Russia and China
Washington has faced growing calls for action in response to Wednesday's attack, which came a year after President Barack Obama declared use of chemical weapons to be a "red line" which would require a firm response.
Russia, Assad's main arms supplier, says rebels may have been behind the chemical attack and said it would be a "tragic mistake" to jump to conclusions over who was responsible.
Its Foreign Ministry said on Monday that it was concerned about a potential U.S. military response and urged Washington to refrain from falling for "provocations".
Iran, the regional Shi'ite Muslim power that has been bankrolling Assad against a revolt led by Syria's Sunni Muslim majority, announced its own "red line", warning Washington of "severe consequences" if it intervened in Syria.
U.S. officials stressed that Obama has yet to make a decision on how to respond. A senior senator, Republican Bob Corker, said he believed Obama would ask Congress for authorisation to use force when lawmakers return from summer recess next month.
In Beijing, Foreign Minister Wang Yi said China supported an independent and objective investigation by U.N. experts into allegations of the use of chemical weapons in Syria, and urged a cautious response and a political resolution to the crisis.
Underlining diplomatic difficulties in forging international agreement, French Foreign Minister Laurent Fabius noted that Russia and China would probably veto a U.N. Security Council move to strike Assad, creating a potential problem under international law for any assault.
British Foreign Secretary William Hague, however, said that it would be possible to respond to a chemical weapon attack without the Security Council's backing.
Obama has been reluctant to intervene in a conflict which began as protests against four decades of Assad family rule but grew into a civil war overtaken by sectarian bloodshed and a strengthening Islamist insurgency with links to al Qaeda.
The death toll of civilians caught in the midst of the violence rises by the hundreds daily. Activist estimates for the alleged poison gas attack ranged from 500 dead to well over 1,000, which would make it the worst chemical weapons attack since Saddam Hussein gassed and killed thousands of Iraqi Kurds at Halabja in 1988.
Turkey, a former Assad ally that is now a major backer of the opposition, said it would join any international coalition even if a decision for action could not be reached at the U.N. .
The experts' mandate is to find out whether chemical weapons were used, not to assign blame, but the evidence they collect, for example about the missile used, can provide a strong indication about the identity of the party responsible.
If the U.N. team obtains independent evidence, it could be easier to build an international diplomatic case for intervention. Former weapons investigators say every hour matters.
By Erika Solomon