Syrian government forces have unilaterally ceased fire in the northern Idlib province, the last major rebel stronghold, Russia said on Sunday, while opposition activists reported continued shelling and airstrikes.

Fighting erupted in Idlib late last month, effectively shattering a cease-fire negotiated by Russia and Turkey that had been in place since September.

Russia has firmly backed President Bashar Assad’s government in the eight-year civil war, while Turkey has supported the opposition.

In a brief statement on Sunday, the Russian Defense Ministry’s Center for Reconciliation of the Warring Sides in Syria said government forces had ceased fire as of midnight. It described the move as unilateral, but did not give details.

The pro-government Syrian Central Military Media said government forces responded to shelling by militants on Sunday on the edge of Idlib. It gave no further details.

The Britain-based Syrian Observatory for Human Rights, an opposition war monitoring group, reported an airstrike on the town of Khan Sheikhoun, saying it inflicted casualties.

The opposition’s Syrian Civil Defence also reported shelling near the town of Jisr Al Shughour without reporting any casualties.

Syrian government forces intensified their attacks as of April 30 on Idlib.

The area is home to some 3 million people, many of whom are internally displaced. The last round of violence also displaced some 180,000 in rebel-held areas.

Meanwhile, Israel launched strikes on southern Syria late Saturday, a war monitor said, prompting air defences into action for the second night in a row.

“Israeli aeroplanes fired at least three missiles from the occupied Golan,” said Rami Abdel Rahman, head of the Britain-based Syrian Observatory for Human Rights.

Two of the strikes targeted a Syrian army brigade which supervises the country’s Quneitra province, he told reporters, while the third missile was destroyed by Syrian defences.

Syria’s official SANA news agency reported “foreign objects coming from the occupied territories (Israel)” which Syrian air defences were “dealing with.”

The Israeli military did not comment on the reported strikes when approached by AFP.

The strikes come a day after Syrian air defence systems intercepted projectiles coming from Israel, SANA reported.

The “hostile targets” were fired late Friday towards Quneitra province which lies close to the Golan Heights, parts of which are annexed by Israel.

Hundreds of strikes have been carried out by Israel in Syria, most of them against what it says are Iranian and Hizbollah targets.

Israel says it is determined to prevent its arch foe Iran from entrenching itself militarily in Syria, where Tehran backs President Bashar al-Assad in the country’s eight-year war.

Israel insists that it has the right to continue to target positions in Syria held by Iran and its Lebanese ally Hizbollah.

Air strikes had stopped in northwest Syria over the past 12 hours, rescuers said on Saturday, as Turkey-backed rebels arrived at the fronts to help fight the army and its Russian ally.

A spokesman for rebels said they rejected a ceasefire proposal from Moscow as long as government forces remain in villages they had advanced into in recent weeks.

There was no immediate comment from Ankara or Moscow.

At least 180,000 people have fled an upsurge in violence in northwest Syria, the last major stronghold of rebels who have fought against Assad’s government since 2011. Government bombing has killed dozens in the past three weeks.

It marks the biggest escalation since last summer between Assad and his rebel enemies in Idlib province and a belt of territory around it.

The region, home to an estimated 3 million people including many who fled other parts of Syria as government forces advanced in recent years, has been partly shielded by a truce deal since last year, brokered by Russia and Turkey. Much of the recent fighting has hit a buffer zone agreed under that deal.

Air strikes have struck 18 health facilities and violence has destroyed at least 16 schools, the United Nations says.

The Syrian government says it is responding to attacks by militants linked to Al Qaeda.

Agencies