The Syrian army on Monday regained control of the rebel-held areas in Homs, a central province which has emerged as a major battleground between Syrian government forces and armed rebels in recent months.

As more people fell victim to escalating conflicts in the country, the UN observer mission expressed its "deep concerns" over the latest deadly clashes and again asked all parties to exercise maximum restraint.

Syria's pro-government media outlets described the recapture of Khalidieh and Bab Sba'a by the government forces as a sign that "it has become more impatient with the bold and brazen attacks by armed rebels."

The UN observer mission said a large number of civilians have been trapped inside the town of Khalidieh and the mission is trying to mediate their evacuation to a safe place.

The UN mission is calling on all sides to halt all kinds of violence to ensure the protection of all civilians and to allow for their evacuation to safe areas, said UN observers' spokesperson Suasan Ghosheh.

The UN observers also reported heavy fighting in Rastan and Talbiseh in Homs.

The observers said the rebel Free Syrian Army had captured soldiers from government forces in Talbiseh, and heavy artillery shelling and machine gun firing were also heard, said Ghosheh.

"We also call on all parties to exercise maximum restraint and to facilitate the entry of UN observers into conflict zone," she said.

Deadly attacks were also reported Monday in other parts of the conflict-torn nation.

Syria's state-run SANA news agency said five government troops were killed by a roadside bomb in the coastal city of Latakia, while activists claimed four people were killed in the army shelling on a mountainous area near the city.

In the eastern province of Deir al-Zour, armed groups blasted a gas pipeline, causing the leakage of around 400,000 cubic meters of gas, but luckily no fire.

The Masaken Barzeh neighborhood in the capital city of Damascus was also rocked by two separate explosions of improvised explosive devices, with one person killed and another severely injured.

In the Damascus suburb of Jaramana, the authorities intercepted a car loaded with 700 kg of explosives, witnesses told Xinhua.

The activists' network Local Coordination Committees said as many as 33 people were killed across Syria on Monday. It was not possible to independently verify the claim.

The most recent UN estimate put the toll from Syria's 15-month unrest at 9,000. The Syrian authorities said that over 2,000 troops were killed while fighting foreign-backed armed groups or by armed attacks on government establishments.

In another related development, the newly elected leader of Syria's opposition umbrella group Syrian National Council (SNC) on Monday urged President Bashar al-Assad to hand over power to Vice President Farouk al-Sharaa.

Assad must leave power and hand it over to the vice president, who is believed not to have been involved in the massacre in the country, said Abdulbaset Sieda.

The 56-year-old Kurd was chosen to head the Istanbul-based SNC over the weekend. He said his appointment showed the election did not discriminate against anyone, ethnically or religiously.

According to Sieda, the Syrian opposition will hold a meeting in Istanbul on June 15-16 to discuss a post-Assad period.

Sieda also expressed the hope that the Free Syrian Army, a group of army defectors, will work to protect the Syrian people from a government crackdown.