The death toll of the nine bombings that rocked two coastal Syrian cities on Monday rose to 154, a monitor group reported on Tuesday.

In the city of Jableh, five bombings rocked a hospital and a bus station, killing at least 106 people.

Most of the bombings in Jableh were carried out at the main bus station, and when the injured were transferred to the city's National Hospital, a suicide bomber wearing an explosive belt infiltrated the emergency room during the melee and blew himself up, killing at least 12 people of the medical team and tens of civilians.

In the city of Tartus, at least 48 people were killed when three bombings, two by car bombs and one by a suicide bomber, rocked near a bus station in the city.

The blasts are considered the first to hit Tartus and Jableh, which have remained largely calm during the country's five-year-old conflict.

It was a big blow to the Syrian government, as both cities considered bastions of the Syrian administration.

The Islamic State (IS) group claimed responsibility of being behind the bombings.