A string of explosions hit two Syrian regime bastion cities on Monday, leaving a number of people dead or wounded, the Syrian Observatory for Human Rights monitoring group said.

Observatory head Rami Abdel Rahman said four blasts, at least one of them a suicide attack, hit the coastal city of Jableh. 

Another three explosions hit the seaside city of Tartus, 60 kilometres (40 miles) to the south, he told AFP.