Updated

Syrian state TV says a military helicopter has crashed at the northern air base of Kweiras, killing all its crew.

The TV report quoted an unnamed military official as saying that the helicopter crashed Sunday as a result of a technical problem while taking off.

The report did not say how many crew members were on abroad at the time of the crash.

Kweiras military air base is in the northern province of Aleppo and is close to the town of al-Bab that is held by the Islamic State group.

Syrian rebels have shot down helicopters in the past.