BEIRUT - Gunmen struck Thursday in Aleppo, Syria's largest city, and in a suburb of Damascus, both strongholds of regime support, killing two army colonels and kidnapping a high-ranking pilot.
State media blamed the attacks on terrorists, the regime's usual description of rebel forces.
Also Thursday, rebels attacked an army truck and killed two soldiers in the central province of Hama, activists said. Fresh clashes also broke out between government troops and army defectors in the country's north and south, and activists said security forces killed at least 16 civilians across Syria on Thursday, including a child and two women.
The violence came as Arab leaders at a Baghdad summit meeting struggled with deep divisions about how to address the Syria crisis. The leaders were expected to pass a resolution calling for a supervised cease-fire and an immediate, daily two-hour stop to fighting across Syria to permit aid to suffering civilians.
Such a resolution would fall short of previous calls by the body that President Bashar Assad give up power, but it would back efforts by U.N.-Arab League envoy Kofi Annan to broker a political solution.
Violence dominated the scene in Syria itself.
Syria's state news agency said four gunmen belonging to an "armed terrorist group" opened fire in broad daylight on the two colonels in the Bab al-Hadid traffic circle in the centre of Aleppo. The high-ranking officers, identified as Abdel-Karim al-Rai and Fuad Shaban, were on their way to work.
In eastern Ghouta, a suburb a few kilometres (miles) from Damascus, gunmen kidnapped pilot Mohammad Omar al-Dirbas, a brigadier, while on his way to work, SANA said. The agency did not say where the three worked or what their positions were.
No one immediately claimed responsibility for the attacks. The Syrian government blames the uprising on terrorists carrying out a foreign conspiracy.
SANA said authorities successfully liberated five military personnel who it said were kidnapped earlier by an "armed group" in the northern province of Idlib.
The anti-Assad uprising has become increasingly militarized since it started last March, but Aleppo has largely been spared clashes between government forces and rebels. However, two mysterious bombings in the city this month killed 29 people. No group claimed responsibility.
The U.N. says more than 9,000 people have been killed since Syrians first took to the streets last year to call for political reforms. Assad's security forces deployed tanks, snipers and pro-regime thugs to quash dissent, but the protests spread. Many in the opposition, led by defectors from the military, have taken up arms to defend their communities and attack government troops.
In Thursday's attack on the army truck in central Hama province, the Britain-based Syrian Observatory for Human Rights said rebels killed two soldiers.
The group said at least five civilians were killed Thursday in army raids on rebellious villages in the Idlib province along Syria's northern border with Turkey. It also reported clashes in the southern town of Dael.
An activist in that town said residents woke up to a huge explosion followed by intense gunfire. He said the fighting and gunfire from government snipers have kept civilians pinned in their homes.
"The security situation is very hard, with snipers on the roofs," Adel al-Omari said over the phone. "It is very dangerous here, and you can't leave your house. Anyone who moves is targeted."
The Observatory said eight soldiers were wounded in the Dael clashes.
The group said security forces killed at least 16 civilians across Syria on Thursday, while another group, the Local Coordination Committees, put the day's death toll at 31, including a child and two women.
Activist claims could not be independently verified. The Syrian government rarely comments on clashes and has barred most news media from working in the country.
