A number of people have been killed in two car bomb attacks in Syria.
The first occurred outside a state-run development agency in Ziyara, a village in the central province of Hama.
State media reported that two people had been killed and 10 others injured, but one activist group said at least 50 soldiers and militiamen had died.
The second blast left four people dead in Mezzeh 86, a predominantly pro-government district in the west of the capital, Damascus, officials said.
The violence came as the main opposition coalition, the Syrian National Council (SNC), announced that it had broadened its membership to more than 400, taking in activists and groups from inside Syria.
The move, announced at a meeting in Qatar, seeks to deflect criticism that the exile-led coalition fails to represent people on the ground.
On Thursday, SNC members will consider a US-backed proposal to set up a new 50-member leadership group that speaks for all the major opposition factions and includes military commanders and local councils.
The SNC would have a minority stake in the new leadership group, but some opposition figures are still sceptical that the effort will succeed.
In Syria, the state news agency Sana reported that there had been a suicide attack in Ziyara, which is situated in the rural Sahl al-Ghab area of the Orontes river valley north-east of the city of Hama.
An official source was quoted as saying a car packed with one tonne of explosives had blown up outside the local Centre for Rural Development, killing two civilians and wounding 10 others.
However, the Syrian Observatory for Human Rights (SOHR), a UK-based activist group, reported that the assailant had targeted a military post in Ziyara and killed at least 50 soldiers and pro-government militiamen.
“The post, located at the Centre for Rural Development, is the largest gathering place for troops and pro-regime militiamen in the region,” SOHR director Rami Abdul Rahman added.
The SOHR said the attack had been carried out by the al-Nusra Front, a shadowy jihadist group which has said it was behind many of the large-scale bombings which have rocked Syria in the past year.
Later, another car bomb exploded in a busy square in Mezzeh 86, killing four people and injuring 20 others, state media said.
Residents told the BBC that two buildings were badly damaged and that shrapnel had been found 500m (1,640ft) away from the scene.
The rebel Aisha brigade said it was behind the attack, which it said targeted pro-government shabiha militiamen.
The BBC’s Lina Sinjab in Damascus says the bombing was the first of its kind in Mezzeh 86, many of whose residents are members of President Bashar al-Assad’s Alawite sect.
The area is heavily guarded by the security forces and the assailant would have had to pass through several checkpoints, she adds.
Palestinian camp deaths
Meanwhile, activists said Syrian government forces had stepped up assaults on rebel strongholds around the capital, Damascus.
War planes and artillery reportedly bombarded the southern districts of Hajar al-Aswad, Tadamon and the Yarmouk Palestinian refugee camp.
Palestinian sources told the AFP news agency that more than 30 people had been killed in Yarmouk in the past 24 hours amid fierce clashes between soldiers and rebel fighters.
Seven died when a mortar landed on a mini-bus travelling along the western edge of the camp, the sources said. At least 24 people were killed when army shells fell on a southern part of the camp on Sunday.
The SOHR also reported that at least 20 rebel fighters had been killed in an air raid on Monday in the northern border town of Harim.
The SOHR is one of the most prominent organisations documenting and reporting incidents and casualties in the Syrian conflict. The group says its reports are impartial, though its information cannot be verified.