Four suicide car bombs have struck Syrian regime targets in the Qalamoun region north of Damascus, killing at least seven soldiers, a monitor and state news agency SANA said.
Wednesday’s attacks come a day after troops loyal to President Bashar al-Assad drove rebels from the nearby strategic village of Qara.
The attacks were claimed by the Islamic State of Iraq and the Levant (ISIL) and Al-Nusra Front, two Al-Qaeda-affiliated groups.
The London-based Syrian Observatory for Human Rights reported two attacks in the town of Nabek.
"At least seven regime troops were killed in the two attacks and five others are in critical condition," Observatory director Rami Abdel Rahman said.
A Syrian security source told the AFP news agency that there was just one explosion at a checkpoint in Nabek.
"The soldiers at the checkpoint stopped a suspicious car and the driver, who was a suicide bomber wearing an explosive belt, tried to escape but was shot dead by soldiers," the source said.
"However, the vehicle exploded," the source added, saying there had been "victims."
Meanwhile, SANA reported two suicide attacks in front of the Bassel hospital in Deir Attiya, a majority Christian town in army control north of Nabek.
"Several guards were killed, then the terrorists broke into the hospital and tried to destroy the equipment but the army managed to chase them down," said SANA.
The Observatory said the rebels had entered the hospital and to capture a wounded officer but were unsuccessful. The group did not report the two car bombs at Deir Attiya.
Government forces backed by Lebanon's Hezbollah have launched a major assault on Qalamoun, a mountainous region straddling key supply lines between Damascus and Homs, as well as rebel smuggling routes criss-crossing the border with nearby Lebanon.
Fighting raged elsewhere in Qalamoun, mainly around the rebel bastion of Yabrud, which the army shelled Wednesday, and Deir Attiya.
Jets launched air strikes on rebel positions around Deir Attiya, said the Observatory, while ongoing clashes killed at least eight opposition fighters.
An estimated 120,000 people have been killed in Syria's uprising, which began with peaceful protests against Assad in March 2011 but escalated into a full-blown insurgency after his troops launched a brutal crackdown.