Syria's state television and an activist group are reporting that an explosion in the northeastern Kurdish town of Qamishli has caused casualties.

The television report did not give details about Friday's explosion.

The Britain-based Syrian Observatory for Human Rights says the blast appears to have been a car bomb that exploded near a building manned by pro-government gunmen.

The blast comes amid clashes between Kurdish gunmen and jihadi groups including members of the al-Qaida-linked Islamic State of Iraq and the Levant.

The Observatory and state TV said there were casualties but gave no figures.