In Afrin, a town near the Turkish border in Syria, a fuel tanker has been detonated on a busy street. Dozens of people were said to have died.
Syrian rebels backed by Turkey controls Afrin.
The tanker was detonated with a bomb in the centre of the city. It was bustling and at least 22 people were killed and 27 injured.
Most of the deaths are civilians, but there would also be six members of a pro-Turkish militia. According to the Turkish Ministry of Defense, 35 civilians were killed.
Turkish news agency Anadolu believes that the Syrian Kurds are behind the attack and relies on government sources for this. The attack has not yet been claimed but may rekindle tensions in northern Syria after a relatively calm period.
Afrin is located in northwestern Syria not far from the Turkish border.
The city was part of a Syrian-Kurdish enclave but was conquered by Syrian rebels in 2018 with the support of Turkey. Besides, many Kurdish residents have been expelled.
In that region, however, there are also tensions between various Syrian rebel groups and the terror group IS also said to have cells there.