BEIRUT (AP) -- An explosion targeted the Syrian Interior Ministry building Wednesday in the capital, Damascus, state TV said. There was no immediate word on casualties.
Rebels fighting to overthrow Syrian President Bashar Assad have been making inroads in their advance toward Damascus, the seat of the government, in recent weeks. Fighting has intensified in the southern districts of the Syrian capital and its suburbs.
The conflict started nearly 21 months ago as an uprising against Assad, whose family has ruled the country for four decades. It quickly morphed into a civil war, with rebels taking up arms to fight back against a bloody crackdown by the government.
According to activists, more than 40,000 people have been killed since March 2011.
Rebels have targeted the center of Damascus with bomb attacks in the past, most dramatically in July when they detonated explosives inside a high-level crisis meeting in Damascus that killed four top regime officials, including Assad's brother-in-law and the defense minister.
An al-Qaida linked group, Jabhat al-Nusra, has claimed many deadly blasts inside Syria.
On the political front, more than 100 countries recognized a new opposition coalition as the legitimate representative of the Syrian people during an international meeting being held in Morocco. The U.S. also has declared the coalition is the "legitimate representative" of its country's people. The moves open the way for greater humanitarian assistance to the forces battling Assad and possibly even military aid.
But the presence of extremist groups among the rebel forces has raised concerns in the U.S. and other nations that are supporting the opposition in Syria but do not want to see extremists gain power in the region. The U.S. has blacklisted Jabhat al-Nusra -- Arabic for Victory Front -- as a foreign terrorist organization and said the group was part of al-Qaida in Iraq.
Al-Nusra fighters appear to be among the most effective fighting forces on the rebel side, spearheading many recent gains.
Western officials have raised concerns that an increasingly desperate Assad might unleash his chemical weapons stockpiles against rebels.
Syria is believed to have a formidable arsenal of chemical weapons, including sarin and mustard gas, although its exact dimensions are not known. Syria is not a signatory to the 1997 Convention on Chemical Weapons and thus is not obliged to permit international inspection.
The government in Damascus has been careful not to confirm it has chemical weapons, while insisting it would never use such weapons against its own people.
On Wednesday, Human Rights Watch accused the Syrian military of using air-delivered incendiary bombs in at least four locations across Syria since mid-November. Such weapons can contain any number of flammable substances, including napalm, thermite, or white phosphorus, and are designed to set fire to objects or to cause burn injuries. They are not considered chemical weapons.