UN inspections underway as US blames Syria for chemical attacks

UN chemical weapons inspectors are set to continue their investigations into last week's attacks in the suburbs of the Syrian capital, Damascus.

The UN team came under sniper fire as they tried to visit an area west of the city on Monday.

The US and its allies are considering military strikes on Syria, although Russia - Syria's ally - has warned against this.

Both the Syrian government and rebels have blamed each other for the attacks.

Medical charity Medecins Sans Frontieres said three hospitals it supports in the Damascus area had treated about 3,600 patients with "neurotoxic symptoms" last Wednesday, of whom 355 died.

In the most forceful US reaction yet, US Secretary of State John Kerry said on Monday there was there was "undeniable" evidence of a chemical attack.

Kerry has signalled his country's intention to act on Syria, describing the use of chemical weapons as a "moral obscenity" and pinning the blame on the Syrian government.

In a strongly worded and emotive statement on Monday, Kerry said that it was "undeniable" that chemical weapons killed hundreds of people last Wednesday near Damascus, adding that the Syrian government must be held accountable.

The statement came hours after a UN team visiting Syria was fired upon while they travelled to the attack site to begin investigations.

Let me be clear. The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders by chemical weapons is a moral obscenity. By any standard, it is inexcusable. And despite the excuses and equivocations that some have manufactured, it is undeniable," Kerry said. 

"The meaning of this attack goes beyond the conflict in Syria itself. And that conflict has already brought so much terrible suffering. This is about the large-scale indiscriminate use of weapons that the civilised world long ago decided must never be used at all, a conviction shared even by countries that agree on little else," Kerry added.

In apparent reference to the Syrian government's denials of responsibility for the attack, Kerry said "anyone who could claim that an attack of this staggering scale could be contrived or fabricated needs to check their conscience and their own moral compass".

"Our sense of basic humanity is offended not only by this cowardly crime but also by the cynical attempt to cover it up. At every turn, the Syrian regime has failed to cooperate with the UN investigation, using it only to stall and to stymie the important effort to bring to light what happened in Damascus in the dead of night," Kerry added. 

He said that the belated response to allow UN inspections was "too late, and too late to be credible".

Under US law, President Barack Obama has the authority to launch air strikes against Syria, but he has to notify Congress first - a process which has begun, according to both sides.

"The administration is actively consulting with members of Congress, and we will continue to have these conversations in the days ahead," Kerry said in his statement on Syria.

The Republican speaker of the House Of Representatives, John Boehner, has had "preliminary communication with the White House about the situation in Syria and any potential US response", his spokesman, Brendan Buck, said.

"The speaker made clear that before any action is taken there must be meaningful consultation with members of Congress, as well as clearly defined objectives and a broader strategy to achieve stability."