Four people were killed and six others injured in a car bomb attack in western Damascus on Thursday, state news agency SANA reported.
The blast hit near a research and testing centre affiliated with the ministry of industry in the Sumaria neighbourhood of the Syrian capital.
"A terrorist car bomb attack killed four people and wounded six others," SANA reported, adding that the blast damaged shops and cars near the centre.
The centre, established in 1965, tests industrial products, its website says.
Since the beginning of the conflict in March 2011, a series of car bombs have targeted Damascus, killing dozens.
The Syrian Observatory for Human Rights watchdog, meanwhile, reported air raids on rebel positions in several parts of the country as well as clashes between regime forces and fighters near Damascus.
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Regime warplanes hit rebel positions in the northwestern province of Idlib, in central Hama province as well as in the norther province of Aleppo and in the coastal city of Latakia, the Observatory said.
Regime forces also carried air raids over the town of Sabina, south of Damascus, while rebels fired rockets into the capita, the Britain-based watchdog said.
It also reported clashes between rebel forces and regime troops in Moadamiyet al-Sham -- one of the sites allegedly hit by chemical attacks on August 21.
Regime troops bombarded also bombarded Daraya, which is also located southwest of Damascus, the Observatory added.
The army has for months been trying to take Moadamiyet al-Sham and Daraya back from the rebels, without success.
In the east of Damascus, regime forces continued to battle rebels in Jubar, where opposition fighters have established a rear base.
The Syrian army also fired mortar shells into the Yarmuk Palestinian refugee camp in southern Damascus, it added.