A string of bombings, including a suicide attack claimed by the Islamic State group, struck in and around several Syrian cities on Monday, killing at least 43 people, mainly in government-controlled areas.

The SANA news agency reported blasts around the coastal city of Tartus, the central city of Homs, the suburbs of the capital Damascus, and the northeastern city of Hasakeh. The attacks were timed closely together, but authorities have not determined whether they were linked. The IS group claimed responsibility for the blast in Hasakeh.

Areas controlled by President Bashar Assad’s forces have seen several bombings and other attacks during the country’s five-year civil war, with many claimed by Al-Qaida-linked militant groups.

One of Monday’s attacks took place in the heavily guarded suburb of Sabbourah, marking a major security breach. SANA said the attack killed one person, while the opposition-run Syrian Observatory for Human Rights said three people were killed.

In Sabboura, a suburb of the capital Damascus, the cleanup work is underway. Pungent smells lingered while workers cleaned the ground with water. Debris from vehicles destroyed by the blasts was scattered on the side of the road.

In the government-held city of Homs in central Syria, at least four people were killed and 10 injured in a car bomb at the entrance to Al-Zahraa neighborhood, which has long been subjected to terrorist attacks.

The Hassakeh bombing, which left five people dead, was caused by an explosives-packed motorcycle at the Marsho roundabout.

The deadliest incident was outside Tartous, home to a Russian naval base on the Mediterranean coast. It was hit by two blasts, the second of which killed 30 civilians and injured another 17.

The Islamic State said that it was behind the Hassakeh attack, which allegedly targeted Kurdish militants, but there have been no immediate claims of responsibility for the blasts in three other areas.

Story by The Associated Press with additional information from CCTV America.