BEIRUT (AP) — Syrian activists say two hospitals have been hit amid a wave of airstrikes on opposition-held areas in the northwest province of Idlib, the largest remaining rebel stronghold in Syria.

The bombardment comes after rebels shot down a Russian fighter jet on Saturday.

The activist-run Edlib Media Center and the Britain-based Syrian Observatory for Human Rights say one of the bombed hospitals was in the town of Kafranbel. They say it was hit on Monday morning.

Also, a spokesman for the Syrian American Medical Society says a hospitals it operates was struck three times on Sunday night.

The spokesman, Mohamad Katoub, says the hospital is in the town of Maaret al-Numan and is no longer operational.

A hospital supported by Doctors Without Borders was damaged in an airstrike last Tuesday.