BEIRUT - Syrian rebels bombed the house of a top member of the country's ruling Baath party in the south on Thursday, killing him and his three body guards, activists said.

The bombing took place in Daraa, where the uprising against President Bashar Assad began in March 2011. Since then, rebels have targeted regime figures and military commanders in the capital, Damascus, and in other places around the country.

The increasing frequency of bombings, a hallmark of Islamic extremists like al-Qaida, has led to concerns about the growing role of Islamist militants in the civil war.

Early Thursday, rebels detonated a car bomb near the house of Hussein Rifai in Daraa, the Britain-based Syrian Observatory for Human Rights said, killing Rifai and his bodyguards. The Observatory relies on reports from activists on the ground.

Syria state-run SANA news agency reported the bombing in Daraa. It said there were casualties in the blast, but did not say if Rafai was among those killed.

The bombing in Daraa came a day after twin suicide car bombs ripped through a Damascus suburb minutes apart, killing at least 34 people and wounding more than 80 others.

Damascus, the seat of Assad's power, has been the scene of scores of car bombs and mortar attacks targeting state security institutions and troops, areas with homes of wealthy Syrians, army officers, security officials and other members of the regime.

In May, two suicide car bombers blew themselves up outside a military intelligence building in Damascus, killing at least 55 people. In July, a bomb hit a building in which Cabinet ministers and senior security officials were meeting, killing the defense minister and his deputy, who was Assad's brother-in-law. A former defense minister also died in the attack.

The revolt in Syria started as peaceful protests but turned into a civil war after brutal crackdowns on dissent by Assad's forces. Activists say more than 40,000 people have been killed.