Rival draft resolutions by the United States and Russia to set up a new expert body to probe chemical weapons attacks in Syria have both failed to pass at the United Nations Security Council.

The votes on Tuesday came amid an escalating war of words between Washington and Moscow and a looming threat of Western military action following a suspected gas attack on the Syrian rebel-held town of Douma on Saturday.

Russia first vetoed a US-drafted text to create a mechanism that would have the authority to assign blame for chemical attacks in the war-torn country.

Twelve council members voted in favour, while Bolivia joined Russia in voting against, and China abstained.

In order to pass, a resolution needs nine votes in favour and no vetoes by the five permanent members: Russia, China, France, Britain or the US.

“Russia contended it could not support the US proposal because it believed that it would lead to bias, and that it was aimed at undercutting what Moscow says is the democratically elected Syrian government,” said Al Jazeera’s Mike Hanna, reporting from the UN headquarters in New York.

This was the 12th time that Russia has used its veto power at the Security Council to block action against the government of Syrian President Bashar al-Assad, a major ally.

Later, a rival Russian bid to create a new inquiry also failed after the proposed resolution only received six votes in favour.

Seven members voted against and two abstained.

“Moscow proposals had been around for a number of months now, but had never gained traction,” said Hanna.

He noted that those opposing it believed that the proposed mechanism “would not be independent”, as its members would have been appointed by Russia, and that “the body itself would not be able to apportion blame or identify perpetrators”.

The Russian draft would have required investigators to report to the Security Council, which could then ascertain responsibility.

Douma attack

Syria’s government and Russia have denied a chemical attack took place in Douma, but rescuers and medics said that dozens of people, including many women and children, were killed.

The US has threatened a “forceful” military response to the attack, while Russia has warned of “grave repercussions” if military action against Syria is launched.

Addressing the Security Council, Nikki Haley, the US ambassador to the UN, said the Washington-drafted resolution “is the bare minimum that the council can do to respond to the attack”.

Her Russian counterpart, Vassily Nebenzia, hit back by saying: “Why do you need this mechanism when you have already appointed the guilty party before the investigation?”

A third resolution, also drafted by Russia, backing the sending of investigators from the global chemical weapons watchdog agency to the site of the suspected attack in Douma also failed to pass later on Tuesday.

“The UN still has nobody that can actually provide accountability for chemical attacks,” said Hanna.

“There is the fact-finding mission, which is able to determine whether an attack has taken place or not but does not have the mandate to apportion blame.”