A suicide car bomb in a northwestern Syrian city held by Turkey-backed rebels killed at least 14 people on Sunday, a war monitor said. Four children were among those killed in the explosion near a mosque in Azaz, a city at the heart of a Turkish zone of influence in northern Aleppo province, said the Syrian Observatory for Human Rights. The attack also wounded more than 20 people, according to the Britain-based monitor. “Many people were leaving evening prayers when the explosion happened,” Observatory head Rami Abdul Rahman told AFP. It was not clear who was behind the attack. Resident Abu Youssef said the explosion struck near the entrance of a market in the centre of the city. “The damage is severe: at least six stores were burned, the storefronts of dozens of other stores were blown out,” he told AFP. The bombing comes one day after a similar explosion killed 10 people and wounded 20 in the northeastern city of Raqa. Turkey launched Operation Euphrates Shield in 2016 and seized more than 2,000 square kilometres in northern Syria including Azaz, clearing the area of the Islamic State jihadists, while preventing any Kurdish advance in the region. Ankara keeps Turkish troops and intelligence forces in the area, and still backs the local police forces.