At least seven people were killed and 30 injured on Saturday in a car blast in a busy marketplace in the rebel-held Syrian town of Azaz near the Turkish border, residents and rescuers told Reuters.

They said the blast occurred during peak late-night shopping after the breaking of the fast during the Muslim month of Ramadan.

"Its timing comes with heavy congestion by shoppers," said Yaseen Shalabi, who was shopping with his family near the site of the explosion.

There was no immediate claim of responsibility.