Syria’s declared chemical weapons are shipped out for destruction.

Syria has handed over the last of its declared stockpile of chemical weapons, which will be destroyed at sea over the next two months, the UN’s chemical weapons watchdog has said.

The Organisation for the Prohibition of Chemical weapons (OPCW) announced that the final 8% of Syria’s acknowledged arsenal of chemical weapons and precursors had been loaded on to a Danish freighter.

The ship, the Ark Futura, is now sailing to the Italian port of Gioia Tauro for a rendezvous with an American vessel, the MV Cape Ray, which is specially equipped to neutralise the most dangerous of the chemical agents at sea.

“The mission to eliminate Syria’s chemical weapons programme has been a major undertaking marked by an extraordinary international cooperation,” said Ahmet Uzumcu, the OPCW’s director-general. “Never before has an entire arsenal of a category of weapons of mass destruction been removed from a country experiencing a state of internal armed conflict. And this has been accomplished within very demanding and tight timeframes.”

However, Uzumcu added that the OPCW was not in a position to certify that Syria no longer had any chemical weapons. The materials removed were those that the regime had declared.

Western governments claim to have intelligence suggesting that Damascus has not admitted to all its chemical arms. An OPCW investigation team has found evidence that chlorine gas was used against civilians in recent months “in a systematic manner”, but the team has been unable to reach the site for further investigation because it came under attack.

Possession of chlorine is not a violation of the chemical weapons treaty, as it is a commonly used chemical, so Syria was not required to list chlorine on its declared inventory. But its use as a weapon is a violation of international law.