The Islamic State group claimed responsibility on Friday for a suicide attack that killed dozens of people near Syria's Al-Bab just hours after rebels seized the town from the jihadists.

In a statement distributed online, the group said its suicide bomber "drove his car bomb into the middle of a gathering of Turkish soldiers and apostates working in Susian", about eight kilometres (five miles) from Al-Bab.

At least 51 people were killed in the blast, most of them civilians, according to the Syrian Observatory for Human Rights monitoring group.