Several bombs went off Tuesday inside a school in the Syrian capital that activists say was being used by regime forces as a security headquarters. Ambulances rushed to the area and an initial report on state media said seven people were wounded.

An amateur video posted online showed smoke billowing from several spots in an area near a major road. The narrator said: "A series of explosions shake the capital Damascus." The authenticity of the video could not be independently confirmed.

Abu Hisham al-Shami, an activist based in Damascus, told The Associated Press via Skype that the "Sons of Martyrs School" had recently been turned into a regime security center. He said government forces use the school as a base to fire mortars at rebellious neighborhoods.

State-run television quoted the director of the school, Mohammed Amin Othman, as saying that two bombs exploded inside the school, wounding seven people and causing minor damage. It said the bombs were planted by "terrorists," the term the government uses for rebels.

Othman said in a statement carried by the state-run SANA news agency that no students were at the school Monday as it will open next week. Although the school year started last week in Syria, Othman said the boarding school will open next week.

The Britain-based Syrian Observatory for Human Rights said 20 people were wounded, some of them seriously, in several blasts at the school. It said most of the wounded were members of military.

As Syria's civil war intensifies, rebels have increasingly targeted security sites and symbols of regime power. In July, a bombing killed four senior security officials including the defense minister and President Bashar Assad's brother-in-law.

Other massive bombings have targeted the Damascus headquarters of security agencies, killing scores of people this year.

A worker outside the school, who refused to be identified, said two diesel tankers exploded inside the school compound, wounding at least four people, one of them seriously. He added that the wounded were rushed to nearby hospitals.

He added that a thick plume of smoke rose over the area and fire reached the fifth story of the building. A nearby theater for the school's students was partially damaged and the blast toppled its ceiling.

Syria's uprising began in March 2011 and has since become a civil war. Activists estimate some 30,000 people have been killed.

The Observatory and the Local Coordination Committees reported violence throughout the country including clashes between troops and rebels near the southern town of Quneitra on the edge of the Israeli-occupied Golan Heights. Both groups said at least seven people were killed in the fighting.

Earlier in the day, the Israeli military said several mortars fired by Syrian government troops targeting rebels hit the Israeli-occupied Golan Heights, but no one was hurt in the shelling.

The incident marks the second time Syrian mortars have landed on the border area since Syria's crisis erupted 18 months ago. In July, mortar shells fell about one kilometer (half a mile) from the Golan boundary.

The Israeli-annexed Golan Heights was captured from Syria in 1967.