At least 18 people have been killed in a truck bomb explosion in the Turkish-controlled town of Al-Bab in northwest Syria.

The explosion near a bus station also wounded at least 75 people, some of them seriously, the UK-based Syrian Observatory for Human Rights said.

Ibrahim al-Haj, a spokesman for the Syrian Civil Defence, a search-and-rescue group that operates in rebel-held parts of Syria also known as the White Helmets, said 82 people were wounded as a result of the blast.