Syrian rebels have launched an attack on an air base in the northern province of Idlib, an activist group said.

The Britain-based Syrian Observatory for Human Rights said the assault on the Taftanaz base began early today.

Observatory director Rami Abdul-Rahman described the attack as one "of the most intense" on the airfield.

In the past few weeks, Syrian rebels have stepped up their attacks on airports around the neighbouring Aleppo province, trying to chip away at the government's air power, which poses the biggest obstacle to the opposition fighters' advances.

Rebels have attacked the Taftanaz base in the past but have failed to capture the facility.