(Adds explosion in Homs)
BEIRUT, April 6 (Reuters) - Two people were killed and eight wounded when mortar fire hit the grounds of the Damascus Opera House in the Syrian capital, state media said on Sunday.
President Bashar al-Assad's forces are in control of central Damascus, but rebels have been able to launch mortar and rocket attacks into the city's centre, sometimes hitting heavily secured upmarket districts and embassy grounds.
"Two citizens were martyred and eight others wounded ... by mortars fired by terrorists at the opera house," the state news agency SANA said, without specifying when the attack occurred.
Elsewhere, at least 13 rebel fighters were killed in a vehicle explosion in the central city of Homs, the British-based Syrian Observatory for Human Rights said, adding that the death toll was likely to rise. There were no more immediate details.
The Observatory, which monitors violence through a network of sources in Syria, said at least five people including three children had also been killed in the Damascus suburb of Douma during shelling by government forces.
In Mleiha, a suburb to the east of Damascus, government war planes carried out air strikes during heavy fighting with rebels.
Elsewhere, government helicopters dropped barrel bombs in the northern province of Aleppo, in Deraa in the south and Latakia in the west, the group said.
Assad's forces also shelled the area around Kasab, a village in the north of Latakia province that rebels seized about two weeks ago.
Late on Saturday, two fighters from the Nusra Front, al Qaeda's affiliate in Syria, were killed in the easterly Hasaka province during fighting around the town of Markadah with an al Qaeda splinter group, the Islamic State of Iraq and the Levant, the Observatory said.
Syria's three-year-old conflict has killed more than 150,000 people and forced millions to flee their homes. (Reporting by Alexander Dziadosz; Editing by Kevin Liffey)