Syrian opposition activists say government warplanes have struck towns and villages in the northwestern province of Idlib, including one near a Turkish observation post.

Wednesday's intense airstrikes came a day after insurgents launched counterattacks on the edges of Idlib, near areas that were recently captured by government forces.

The Britain-based Syrian Observatory for Human Rights says the airstrikes targeted the town of Maaret al-Numan and villages near it, with one strike hitting close to one of Turkey's 12 observation posts in Idlib.

The Syrian Civil Defense said another airstrike hit a market in the town of Sarqeb, wounding eight people.

A government offensive that began on April 30 has killed more than 2,000 people and displaced half a million. Many have fled further north toward the border with Turkey.