Beirut: Nine people, mostly civilians, were killed on Saturday in an explosion in the city of Idlib in northwestern Syria but the cause was not immediately clear, a war monitor said.

The blast left 26 more people wounded, according to the Britain-based Syrian Observatory for Human Rights, which relies on a network of sources inside the war-torn country.

In recent months, several explosions have rocked Idlib province, which has witnessed infighting between competing hardline groups opposed to Bashar Al Assad.

The most prominent armed group is Hayat Tahrir Al Sham, which is led by Syria’s former Al Qaida branch.

Syria’s war has killed more than 400,000 people and displaced millions since it started in 2011 with a brutal crackdown on anti-regime demonstrations.