Beirut: A powerful blast killed four people Saturday in Qardaha, the heartland of Syria`s ruling Assad clan, a monitoring group said, adding that the origin of the explosion was unknown.
The explosion, the first to hit the centre of the western town since the outbreak of Syria`s civil war in 2011, hit an area near a hospital, said the Syrian Observatory for Human Rights.
The Britain-based group said it was unclear whether the explosion had been caused by a car bomb or by rocket fire.
The explosion "killed four people -- a nurse, a hospital employee and two soldiers", said Observatory director Rami Abdel Rahman.
The outskirts of Qardaha have previously come under rebel rocket fire.
Qardaha is home to a mausoleum containing the graves of President Bashar al-Assad`s father and predecessor, Hafez, and brother Bassil.
The clan has ruled Syria with an iron fist for more than 40 years.
Syria`s war has killed more than 210,000 people, and forced half the population to flee their homes.