The Russian military on Sunday said the Syrian regime’s forces had ceased fire “unilaterally” in northwestern Idlib province, where the UN fears a “humanitarian catastrophe.”

“From 00:00 on May 18, Syrian armed forces unilaterally ceased fire in the Idlib de-escalation zone,” the Russian military’s center for reconciliation in Syria said in a statement.

“However, firing targeting government forces’ positions and civilians in the provinces of Hama, Latakia and Aleppo continues.”

The statement came after Britain, France, the US and eight other countries at the UN Security Council warned on May 10 of a potential humanitarian catastrophe from an offensive in Idlib region.

Western powers fear that the Moscow-backed Syrian regime will launch a full-scale offensive, despite an agreement reached with Turkey, which backs rebel forces, to set up a de-escalation zone in Idlib.

The Syrian Observatory for Human Rights, however, said that shelling by the regime’s forces had continued on Sunday, despite the announcement by the Russian army.

The Syrian state agency Sana said rockets and mortar shells were fired at the northern part of Hama province by “terrorist groups,” using the regime’s term for jihadists and rebels.

It added that the army responded with fire that destroyed positions held by Syria’s former Al-Qaeda affiliate Hayat Tahrir al-Sham (HTS).

The group controls most of Idlib province as well as parts of neighboring Aleppo, Hama and Latakia provinces.

Syrian forces and their Russian allies have stepped up air strikes and shelling in the jihadist-controlled Idlib region since late April, raising alarm over a possible looming full-on offensive by Damascus to seize the territory.

About three million people live in Idlib, the largest area still outside the control of the Syrian government.

– with reporting by AFP