A suicide car bomber blew himself up on Tuesday in Damascus, killing at least three people and wounding five others, the official news agency SANA reported.
The bomber blew himself up in a van in the Rukneddin neighbourhood in northern Damascus, it added.
Rami Abdel Rahman, head of the Syrian Observatory for Human Rights said the blast took place near a building housing army food supplies, DPA reported.
Ambulances were rushing to the scene, while all roads leading to the area were closed by security forces, activists said.
Earlier, mortar shells fell on a school in Baramkeh area killing four people, among them a child, and wounding 12.
Television showed a hole inside the wall of the school and shrapnel on desks and shattered glass on the classroom floor.
The shelling, which targeted the centre of Damascus for the second consecutive day, also hit near the offices of SANA.
Further mortars hit the mainly Christian area of Bab Sharqi in the old city, locals said.
The shelling came a day after the Free Syrian Army warned Damascus citizens to stay away from governmental and army buildings in Damascus.