Army defectors in southern Syria battled loyalist forces backed by tanks Sunday in a major armed confrontation near the Jordanian border.

Residents and activists said government troops mainly from Syria's 12th Armored Brigade stormed the southern town of Busra al-Harir overnight. The British-based Syrian Observatory for Human Rights said three military vehicles were burned in the clashes. The group said similar battles took place Sunday in several other parts of the south.

Reuters quoted local residents as saying defectors had been hiding and attacking military supply lines from the area, provoking the government assault.

The Observatory said separate clashes between government troops and deserters in the northwestern town of Kfar Takharim saw two civilians killed and two troop transport vehicles set ablaze.

Meanwhile, several regions across Syria observed the opposition's call for a general strike Sunday, the first working day of the week.

Rights groups said that in several towns, security forces attempted to open shops by force and carried out arrests, although business continued as usual in the capital, Damascus.

The opposition called the nationwide strike in an attempt to bring down the regime through civil disobedience. The opposition Local Coordination Committee has urged citizens to hold sit-ins, close facilities and to refuse to work in the public sector.

On Saturday, Syrian forces opened fire on protesters gathered at a funeral for a child, killing at least four people.

Activists said the unrest in northwestern Idlib province was among several deadly incidents Saturday. They said three civilians were killed in the central Homs region after gunfire erupted near a security checkpoint. Witnesses say Syrian forces have increased their presence in the flashpoint region.

Opposition activists say anti-government related unrest also left at least three people dead in other regions.

Separately, the state-run SANA news agency says three security force members killed by “armed terrorists” in Homs were buried on Saturday. The government has blamed much of the country's unrest on gunmen and militants.

Syrian President Bashar al-Assad has been facing mounting international pressure to end a crackdown on dissent that the United Nations says has claimed more than 4,000 lives.