More than 100 people were killed in a series of blasts that rocked regime-held areas on the Syrian coast Monday, activists and a monitoring group said.
"More than 48 people were killed in Tartus and 73 others in Jableh located on the outskirts of the province of Latakia," the head of the Britain-based Syrian Observatory for Human Rights, Rami Abdel Rahman, told dpa.
The observatory said the blasts targeted bus and taxi stations in both cities, as well as the power company and the entrance to a hospital emergency department in Jableh.
Islamic State supporters on social media circulated a claim of responsibility for the bomb attacks.
"Attacks by Islamic State fighters hit gatherings of Alawites in the cities of Tartus and Jableh on the Syrian coast," the statement reads, referencing the Alawite sect of President Bashar al-Assad, which has a strong presence in coastal Syria.
The claim, which was ascribed to Islamic State's Aamaq news agency, could not be independently verified by dpa.
The port of Tartus has been used for years by the Russian Navy. The port has been busy recently receiving and delivering supplies to the Russian Army based in Syria.
Jableh is near the main Hmeimim airbase used by the Russians for launching airstrikes across Syria.
Both areas are heavily populated by Alawites. Both cities are also crowded with refugees who have escaped other areas over security concerns.
The observatory said refugees who are living in Tartus and Jableh fear that the regime may carry out a series of arrests among their ranks because some of them are Sunni Muslims.
The Tartus blasts came a few minutes after at least two explosions rocked Jableh, the observatory said.
"The number of casualties is likely to increase as there are tens of wounded in both blasts," an activist in the province of Latakia, who goes by the name of Abu Mohammed, told dpa.
Rami Abdel Rahman has put the number of wounded at 200.
The state-run Syrian News Agency (SANA) confirmed the blasts and said that the explosion in Tartus took place in a residential area.
According to SANA, first a car bomb went off in the area where a transportation station is located in Tartus; and then a few seconds later a suicide bomber blew himself up in the area, causing several casualties.
"A third blast was carried out simultaneously by a suicide bomber on the western side of the station, which was targeted by the first two blasts," SANA added.
The agency said that several blasts also rocked the area of Jableh. Syrian-State TV further reported that one of the Jableh blasts hit a hospital in the area.
Pictures aired by state television showed heavy damage in the areas where the blasts took place and blood pools covering the streets.
Other television footage showed minibuses, vans and taxis ablaze, while panicking people were running and shouting for help.
"These are the worst blasts to hit Tartus area in 30 years," Abdel Rahman said.
In April 1986, a wave of deadly bomb attacks hit Tartus and Mashtal Helou. The blasts then targeted buses transporting Syrian Army cadets.
At least 27 cadets were killed in the blasts which were at the time blamed on what the regime called "Israeli agents."