A car bomb hit a checkpoint in a western suburb of Damascus on Wednesday, causing multiple casualties among the troops manning it, the opposing UK-based Syrian Observatory for Human Rights said.

A car bomb hit a checkpoint in a western suburb of Damascus on Wednesday, causing multiple casualties among the troops manning it, the opposing UK-based Syrian Observatory for Human Rights said.

The bombing in the Dumar suburb came as much of Syria was plunged into darkness after an attack by rebels near Damascus has caused a power outage across Syria, state news agency SANA quoted the electricity minister as saying.

"A terrorist attack on a gas pipeline that feeds a power station in the south has led to a power outage in the provinces, and work to repair it is in progress," Emad Khamis said.

In a different context, Damascus said on Wednesday that no foreign party will be involved in deciding the country's leadership.

"The Syrian people are the only ones who can choose their leader, and who can decide on Syria's present and future," the foreign ministry said.

"The Syrian people will not allow any foreign party to impose itself... in choosing a government, or in determining its powers and tasks."