At least 28 civilians were killed in air strikes on Syria’s planned safe zone in a bombing campaign against militants, a monitor said on Saturday.

Four children were among the dead in the overnight airstrikes on the town of Armanaz, in Idlib province near the Turkish border, the Syrian Observatory for Human Rights said.

The airstrikes were triggered by an offensive by jihadist fighters led by Al-Qaida’s former Syrian affiliate launched against government-held villages in neighbouring Hama province.

The jihadists control nearly all of Idlib province after driving out Islamist former allies earlier this year.

Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan agreed on Thursday to step up efforts to establish a safe zone in Idlib as part of a wider agreement struck in May.

Three other safe zones have already been set up — in Eastern Ghouta near Damascus, parts of the south and some areas of the central province of Homs.

The de-escalation agreement excludes both the Islamic State group and Hayat Tahrir al-Sham, the alliance dominated by Al-Qaeda’s former Syrian affiliate.

The Islamic State group is under attack in its remaining strongholds in eastern Syria by both Russian-backed government forces and US-backed fighters.