MEMBERS of the Syrian Civil Defense, also known as the “White Helmets,” inspect damage at a health facility that was hit by a reported Russian air strike after midnight in Urum al-Kubra in northern Aleppo province on Saturday. AFP

BEIRUT, Lebanon — At least 40 jihadist leaders were killed Saturday in Syria after a missile attack targeted their meeting in the northwestern province of Idlib, a war monitor said.

“A missile attack targeted a meeting held by the leaders of Hurras al-Deen, Ansar al-Tawhid and other allied groups inside a training camp” near Idlib city, said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.

The attack killed “at least 40” jihadist leaders, the Britain-based monitor said.

It was not immediately clear who was behind the attack, or if the missiles were launched from war planes or positions on the ground, the Observatory said.

An AFP correspondent saw clouds of black smoke rising over the area after blasts rocked the jihadist stronghold.

Ambulances rushed to the site of the attack, which was closed off to journalists, he said.

The al-Qaeda-linked Hurras al-Deen and their allies Ansar al-Tawhid both operate in the Idlib region, where bombardment by Damascus and Moscow came to a halt Saturday morning after the government agreed to a Russian-backed ceasefire following four months of deadly bombardment.

Both groups are members of a joint jihadist operation room that also includes al-Qaeda’s former Syria affiliate, Hayat Tahrir al-Sham.