The Islamic State launched a series of deadly suicide bombings across Syria Monday, killing at least 48 people.
The series of coordinated attacks happened in the government-held areas of Damascus, Homs and Tartous, according to CNN.
The ISIS-run Amaq news agency said the group was behind the six suicide bombings and a remotely-detonated bomb. The attacks were timed to happen during rush hour.
Syria's state TV said 48 people were killed in blasts, but the British-based Syrian Observatory for Human Rights put the death toll at 53.
Of those killed, at least 30 died in two explosions on a highway bridge near the government stronghold of Tartous, according to CNN.
The first car bomb struck a bridge and in the second attack, a suicide bomber struck a crowd that had gathered nearby, according to the Syrian Arab News Agency.
In Homs, a car bomb struck a military checkpoint, killing three soldiers and a civilian. Homs is Syria's third-largest city and is primarily under government control.
Police Gen. Jamal A-Bitar told Syrian TV he believes one bomb was detonated before it reached its intended target. A jeep carrying six militants blew up when a soldier stopped the vehicle near Damascus.
A-Bitar said he believe the militants were on their way to the capital to carry out an attack.
ISIS also detonated a bomb in Qamishli, targeting Kurdish fighters.
The Syrian Observatory for Human Rights confirmed the explosion, bust said there were no casualties in that attack.
The Associated Press contributed to this report.