The Organization for the Prohibition of Chemical Weapons refuses to send its experts to Aleppo to check substances used by rebels in attacks. The move was “seemingly done under pressure from our Western colleagues,” Russia’s foreign minister said.

“Russian specialists found that militants in east Aleppo used ammunition with poisonous substances, with the ammo targeting west Aleppo. The collected samples leave no doubt that it’s a toxic agent,” Sergey Lavrov said at a press conference with his Belarusian counterpart in Minsk, as cited by Interfax.

Read more

However, when the Russian Ministry of Defense addressed the leadership of the UN watchdog OPCW “with the demand to urgently send its experts to Aleppo to participate in the sample analysis,” the organization “refused to carry out this simple task, citing security issues.”

The underlying reason behind this, Lavrov said, seemed to be “tremendous pressure from our Western colleagues,” because “our and Syrian sides guaranteed security [for the experts].”

Russia is now working on the possibility of delivering the samples for analysis to The Hague, Lavrov added.

“It will make it hard [for them] to back out,” the minister said, as quoted by TASS.

Lavrov’s statement comes a day after the Ministry of Defense spoke about the evidence of chemical attacks by rebels, and stressed that the OPCW was refusing to cooperate.

Ministry spokesperson Major General Igor Konashenkov said that Russian experts collected bioassays from four Syrians injured in the attacks, and made the shocking discovery earlier this month.

Responding to media inquiries about the matter, the OPCW spokesperson confirmed that the organization had "recently received an offer from Russian authorities to provide some samples and other material in relation to an incident of alleged use of chemicals as weapons in Aleppo."

Yet, citing "security situation in and around Aleppo," the watchdog said it expected "to receive such material in Damascus or The Hague."

In fact, Russian top brass has been warning since September that the militants might use chemical weapons against civilians in Aleppo, and in October, Syrian state media reported toxic gas having been used against a government-held area in the city.

Fifteen people were injured back then, and a local doctor told RT that the symptoms could be those observed after the use of chlorine gas.

Over the past few years, the Syrian government has often come under fire over claims of its alleged use of chemical weapons to attack the rebel-held areas – from activists and the UN, as well as the US State Department.

WATCH MORE: