Regime airstrikes and artillery fire in northwestern Syria, including on schools in the city of Idlib, killed 19 civilians on Tuesday, a war monitor said.

The Syrian Observatory for Human Rights said eight children were among those killed in the raids on Idlib city and the towns of Binnish and Maarat Misrin.

Earlier Tuesday, the White Helmets civil defense group said three civilians were killed and nine others injured after Russian jets targeted the town of Termanin in Idlib and the town of Darat Izza in Aleppo governorate.

While fires after the airstrikes were put out by civil defense teams, search and rescue activities are continuing.

The Bashar Assad regime and its allies have continued intensified air and land attacks on civilian settlements in the Idlib de-escalation zone.

In September 2018, Turkey and Russia agreed to turn Idlib into a de-escalation zone in which acts of aggression are expressly prohibited.

Since then, however, more than 1,800 civilians have been killed in attacks by the regime and Russian forces who flouted a 2018 cease-fire and a new one that began on Jan. 12.

More than 1.7 million Syrians have moved near the Turkish border due to intense attacks over the past year.

Turkey remains the country with the most refugees in the world, hosting more than 3.7 million migrants since the start of Syria's civil war in 2011.