Updated

The U.S. and Western powers on Monday clashed with Russia and others over whether the global chemical weapons watchdog could start apportioning blame for poison gas and nerve agent attacks.

At a heated session of the Organization for the Prohibition of Chemical Weapons' annual conference, both sides bitterly fought over a June decision for the group to set up a new investigative team which could name the perpetrators of chemical attacks — a major change in the group's rules.

Russia and China said the widely-backed June decision to allow the organization to identify those responsible should be reviewed to ensure it didn't go beyond the OPCW mandate.

The U.S. ambassador to the watchdog, Kenneth Ward, complained that "a tsunami of chemical weapons" had been used this year, especially in Syria, an ally of Russia, and called Moscow's attempts to undo the decision "pungent hypocrisy."

Britain and its allies also have accused Moscow of using a Soviet-era nerve agent in an attempted assassination of former spy Sergei Skripal and his daughter in Salisbury earlier this year. Russia denies the allegation.

Britain's ambassador, Peter Wilson, said a Russia-Chinese proposal to review the decision "is clearly designed to obstruct and delay implementation" of the decision.

Russian envoy Alexander Shulgin said the new team would wield unlawful powers within the OPCW and on Monday called for an expert group to assess the viability of the decision, something the U.S. insisted would hamstring the development of the team. Wilson said that the Russian move would "undermine" plans to set up the team.

Last June, an 82-24 vote among OPCW members provided more than the necessary two-thirds majority to give the group the mandate to name the parties it found responsible for chemical attacks.

With Russia's opposition on Monday, Ward said that Russia and China made "an attempt to re-litigate what happened in June." He said that both nations "are trying to turn back the clock of history."

One allegation still being investigated by weapons inspectors is the suspected chemical attack in April in the Syrian town of Douma. An interim report said that weapons inspectors found "various chlorinated organic chemicals" at the site of the alleged Douma attack.

The OPCW made headlines last month when Dutch authorities revealed that they had foiled an alleged plot by Russian spies to hack into the organization's Wi-Fi network using equipment stashed in the trunk of a rental car parked at a hotel next to the OPCW headquarters. Russia denied any wrongdoing.

___

Mike Corder contributed from The Hague, Netherlands.