Syrian state TV and opposition activists say the army has captured a strategic town in northern Syria believed to be the home of a chemical weapons production facility and storage sites.

The town of Safira has been the scene of three weeks of intense fighting as the army kept trying to retake it from rebels who have been in control there for more than a year.

Although unconfirmed, Safira is believed to be one of two sites that chemical weapons inspectors were unable to visit because of security concerns. The town is also strategic as a supply route for Syrian government forces in the contested city of Aleppo.

Syrian activists in Aleppo province confirmed Friday that rebels withdrew from Safira overnight under heavy fire, leaving it to government troops.

On Thursday, the global chemical weapons watchdog said Syria has destroyed critical equipment for producing chemical weapons and poison gas munitions.

The announcement by the Organization for the Prohibition of Chemical Weapons came as fierce clashes raged in the country's north, close to one of the sites where toxic agents are believed to be stored.

It also came one day ahead of the November 1 deadline set by The Hague-based organization for Damascus to destroy or "render inoperable" all chemical weapon production facilities and machinery for mixing chemicals into poison gas and filling munitions.

Earlier this week, the inspectors said they had completed their first round of verification work, visiting 21 of 23 sites declared by Damascus. They were unable to visit two sites because of security concerns, the inspectors said.