Regime and Russian air strikes and shelling have killed at least 28 people including seven civilians in embattled northwest Syria, the Syrian Observatory for Human Rights said Friday, despite a ceasefire announced by Moscow. The civilians were killed in regime air strikes and shelling on the south of Idlib province and the north of Hama province Thursday, said the war monitor. Russian and regime air strikes also killed 21 militants in the same region the same day, the Britain-based monitor added. The Idlib region of some three million people is supposed to be protected from a massive regime offensive by a buffer zone deal that Russia and Turkey signed in September. But it was never fully implemented, as militants refused to withdraw from a planned demilitarised zone. In January, the Hayat Tahrir al-Sham alliance extended its administrative control over the region, which includes most of Idlib province as well as adjacent slivers of Latakia, Hama and Aleppo provinces. The Syrian regime and Russia have upped their bombardment of the region since late April, killing more than 360 civilians, according to the Observatory.