Forces loyal to Syrian President Bashar al-Assad have recaptured a Christian town on the main highway north of the capital, the army said, putting them back on the offensive in the strategic region near the Lebanese border, according to Reuters.

Assad's forces have made advances in recent months and are trying to secure the highway linking Damascus to the coastal heartland of his Alawite minority sect, but faced a setback last week when they lost the town of Deir Attiya to al Qaeda-linked fighters.

The town is in the mountainous Qalamoun area overlooking the highway near the Lebanese border, a region that has emerged as the main battleground as Assad and his opponents try to secure a strategic advantage ahead of a peace conference in January.

"Units from the army managed to defeat terrorist groups which had infiltrated Deir Attiya... The operation eliminated many terrorists from different nationalities," a Syrian army statement said. The government refers to opposition fighters as terrorists.

The statement said soldiers were pursuing the gunmen in nearby areas in an attempt to secure the highway. Assad's military campaign in Qalamoun was jolted last week by twin suicide attacks from al Qaeda-linked groups on army posts in the nearby town of Nabak.

Taking advantage of confusion among Assad's soldiers, Islamist fighters launched coordinated attacks and pushed the troops out of Nabak and Deir Attiya, whose residents had not joined the revolt against Assad.

The army brought in reinforcements and launched a counter offensive three days ago, retaking Deir Attiya on Thursday, Nov 28 and battling rebel fighters in Nabak on Friday.

In recent days a sudden rebel surge from the southern front pushed government forces and Hezbollah fighters out of several villages they captured in the past few months.

Activists have reported heavy fighting on the outskirts of the town of Otaiba, which rebels had used as a conduit for arms supplies into Damascus until the army seized it in April.

Syrian state television said on Friday the army had foiled "a terrorist attempt to infiltrate from Jordan", suggesting rebels were trying to further reinforce the battle around Damascus, just 70 miles north of the Jordanian border.

Casualties on both sides have been heavy, with Hezbollah losing at least 25 fighters in eastern Ghouta over the last week according to security sources in Lebanon. Those killed included the nephew of a minister in Lebanon's caretaker government.

The Syrian Observatory for Human Rights said 230 people were killed across Syria on Thursday, including 162 fighters on both sides. Many were killed in the battles around Ghouta and Qalamoun, the British-based monitoring group said.

Western powers are trying to bring Assad and his opponents together for a peace conference in Geneva on January 22 to end the fighting. Both sides said this week they will attend.