Syria gas attack probe stalls as Russia accused of tampering with evidence

Britain's embassy to the Netherlands said Assad's regime and its top ally had not yet allowed a team from the Organisation for the Prohibition of Chemical Weapons (OPCW) to enter the site of last Saturday's massacre in Eastern Ghouta.

The head of the global watchdog Ahmet Uzumcu had briefed emergency talks about the deployment of the team, which arrived in Damascus on Saturday.

But "Russia and Syria have not yet allowed access to Douma. Unfettered access essential," the British delegation based in The Hague said in a tweet on Monday.

Uzumcu said "the Syrian regime and the Russians were citing security concerns," ambassador Peter Wilson told a press conference.

The Kremlin dismissed claims that Russia was impeding access as "groundless", President Vladimir Putin's spokesman Dmitry Peskov said, adding that Moscow was in favour of "an impartial investigation".

Meanwhile, the US has raised concerns Russia may have visited Douma and "tampered with" evidence.

"It is our understanding the Russians may have visited the attack site," US ambassador Ken Ward told the emergency  in The Hague.

"We are concerned they may have tampered with it with the intent of thwarting the efforts of the OPCW fact-finding mission to conduct an effective investigation," he added in his speech, a copy of which was sent to AFP.

The investigation follows a round of punitive airstrikes carried out by the US, UK and France at the weekend on Syrian regime chemical storage facilities. 

British ambassador Wilson urged the OPCW "to act to hold perpetrators to account", saying failure to do so "will only risk further barbaric use of chemical weapons, in Syria and beyond".

"The time has come for all members of this executive council to take a stand," Wilson said, adding "too many duck the responsibility that comes with being a member of this council".

He repeated that the UK, together with the United States and France, on Saturday had struck at a "limited set of targets".

The alleged chemical weapons attack that President Donald Trump branded the "crimes of a monster" left at least 49 people dead, according to medics and rescue groups.

"Shameful"

Since Syria joined the OPCW in 2013, "we have sought to use diplomatic channels ... to stop chemical weapons use in Syria but our efforts have been repeatedly thwarted," Wilson said.

It was "shameful" that a lack of accountability for the April 2017 attack on Khan Sheikhun "can only have reassured the Syrian regime that the international community was not serious in its stated commitment to uphold the norm against chemical weapons use," he added.

Both Syria and Russia have denied using chemical weapons and have blamed the rebels on using it on themselves to whip up international condemnation.

Putin has not announced any retaliatory measures to the US-led strikes, however Russia has called for an emergency session of the UN Security Council.

Earlier in the year, a report linked Syria's largest sarin nerve agent attack in August 2013, which left hundreds dead, to the Syrian regime chemical stockpile.

Damascus joined the OPCW and agreed to destroy its 1,300-tonne stockpile of industrial munition, under Russia's supervision, following a US-Russian deal.

Despite agreeing to the deal, inspectors have found evidence of an ongoing chemical weapons programme in the country, including systematic use of chlorine barrel bombs and sarin.

Previously, Russia has said it had dispatched experts to Douma who had not found any evidence of chemical weapons use. Later, the Russian Foreign Minister Sergei Lavrov claimed that Moscow had "irrefutable" evidence that the deadly chemical weapons attack in Syria's Douma was staged with the help of a foreign secret service. The Russian military added on Friday that the attack was staged on orders from London.

For its part, France has cited "overwhelming testimony" and extensive analysis by French intelligence services and laboratories that pointed to the Assad regime involvement.

Around 500,000 people have died and millions made homeless in seven years of fighting in Syria, which was sparked when regime forces brutally put down peaceful protests in 2011.