As fighting raged between rebels and President Bashar al-Assad's forces in a suburb of the Syrian capital, Damascus, the head of the International Committee of the Red Cross was preparing to meet with Russia's foreign minister over ways to get humanitarian aid into Syria.
There were reports of heavy exchanges of fire overnight between government forces and rebels of the Free Syrian Army outside the capital, and helicopters were said to be circling the area where several embassies and government buildings are located.
There were no initial reports of casualties.
The latest reports of violence comes after a bloody weekend that saw dozens die in a series of attacks in Damascus and the second-largest city, Aleppo, in the north of the country.
Meanwhile, the head of the International Committee of the Red Cross, Jakob Kellenberger, was expected to meet with Russian Foreign Minister Sergei Lavrov in Moscow later in the day.
Kellenberger has said a daily two-hour cease-fire is needed to evacuate the wounded from besieged areas like Homs, the besieged city in western Syria.
A joint mission by the Organization for Islamic Cooperation and United Nations is already in Syria to assess the country's humanitarian needs.
The UN says the yearlong uprising and resulting crackdown by Assad's regime has killed some 9,000, with another 30,000 having fled the country and 200,000 more Syrians internally displaced.
A team of experts has been dispatched to Damascus by Kofi Annan, the special envoy on Syria for the United Nations and Arab League. A cease-fire and international monitoring mission is on their agenda.
Annan warned on March 16 that the crisis could spill over into neighboring countries and urged international powers to lay aside their differences and back his peace initiative.
Lavrov on March 17 urged Syrian authorities to back Annan's peacemaking efforts "without delays."
A car bomb in Syria's second city, Aleppo, on March 18 left two dead and 30 wounded, according to the state news agency SANA. The government blamed the blast on terrorists.
Opposition activists, however, accused the government of staging the attack to portray the protesters as terrorists.
The semiofficial news channel Al-Ikhbariya said security forces had secured information about the planned attack and had been moving residents out of the area when it went off.
It said the car had been packed with 200 kilograms of explosives. The strength of the explosion blasted open building fronts.
The car bomb attack comes a day after double blasts in Damascus killed 27 and wounded nearly 100 more.
In Damascus, hundreds came out on March 18 to mourn the victims of the Damascus explosions.
Activists told Reuters security forces arrested people at a march of more than 200 when protesters began shouting, "The people want to topple the regime."
Among those reported to have been arrested was Muhammad Sayyed Rassas, a leader of the National Coordinating Body for Democratic Change, an opposition group that supports dialogue between the opposition and Assad.
Meanwhile, the Stockholm International Peace Research Institute (SIPRI) says Syria imported nearly six times more weapons in 2007-11 than in the previous five-year period. Russia accounted for 72 percent of Syria's weapon purchases, including air-defense systems and antiship missiles, according to SIPRI.
Based on AP and Reuters reporting