At least 11 civilians were killed in Syria's second city Aleppo in one of the highest single tolls since a fragile truce came into force, a monitor says.

An Islamic State militant executes his mother in public in the Syrian city of Raqqa because she encouraged him to leave the group, the Syrian Observatory for Human Rights reports.

A Syrian government warplane crashes in a marketplace in the north-western town of Ariha, killing 17 people.