A fire at a medical clinic in northeast Syria has killed 27 people, mostly children, say reports.

Around 30 people were also injured when a fuel tank exploded at the Maysalun clinic in Qamishli, a Kurdish city on the Turkish border.

Juan Mohammed, a Kurdish official in the nearby city of Hassakeh, said the clinic was packed with children waiting to get vaccinated against polio.

State news agency SANA said dry branches caught fire and spread to a fuel tank, causing “significant material damage” in the blast.

“At least 27 people were killed … and at least 30 people are being treated for burns,” it said, citing a doctor at the scene.

Control of Qamishli is divided between Kurdish forces and troops loyal to Syrian President Bashar al Assad.

The city has escaped much of the violence of Syria’s civil war, which has left more than 220,000 people dead since it began in March 2011 with anti-government demonstrations.