LONDON — International inspectors said Thursday that they had verified the destruction of all but one of 23 chemical weapons sites declared by Syrian authorities under a deal brokered by Russia and the United States, determining that one of the two sites they had been unable to reach earlier had been “dismantled and long abandoned.”
The inspectors, from the Organization for the Prohibition of Chemical Weapons, said their finding that the 22nd site, in the northern Aleppo region, had been destroyed was based on images from sealed cameras used by Syrian personnel who were working under their inspectors’ guidance.
The site was one of two listed as too dangerous to visit because of the country’s civil war when the inspectors said a week ago that they had certified that Syria had disabled all the chemical weapons production and mixing facilities it had declared to the organization, which is based in The Hague.
At the time, the inspectors said they and UN officials had visited 21 of the 23 sites and believed that chemical-making equipment at the remaining two had been moved to other sites.
In an update Thursday, the chemical weapons watchdog group said the geographical location of the site and the time stamp for the images taken by the cameras had been authenticated.
“As per the declaration by Syria, the site was confirmed as dismantled and long abandoned, with the building showing extensive battle damage,” the statement said.
When asked to further explain how the organization had ensured the accuracy of the images that were captured by the cameras, a spokesman, Christian Chartier, said in an e-mail that the verification procedure had eliminated the possibility of any mistake or deception.
“The cameras had been rendered tamper-proof and equipped in such a way that we knew at all times where they were,” the spokesman said.
“Thanks to these devices, the footage could not be edited. It was then checked against satellite imagery and cross referenced with other data.”
The dismantling of weapons production facilities is a precursor to the destruction of about 1,300 metric tons of chemical weapons by mid-2014 under a deal that was worked out by Moscow and Washington that lifted the threat of US military strikes after chemical weapons were used in an attack in a Damascus suburb in August.
The United States and its allies blamed Syrian government forces for using the nerve agent sarin, but President Bashar Assad accused rebels forces of responsibility for the attack, which killed hundreds.
While the relatively rapid pace of dismantling chemical weapons facilities has drawn headlines, the civil war, which has claimed more than 110,000 lives since March 2011, has continued relentlessly with conventional weapons, exacting a daily toll.
According to the United Nations, 6.5 million Syrians have been driven from their homes inside the country and millions more have sought refuge across its borders in neighboring lands.
The next deadline facing the Syrian authorities is Nov. 15, when they are supposed to produce a plan for the destruction of their stockpile of chemical weapons.