AMMAN (Reuters) - Dozens of people were feared dead or wounded after a car bomb exploded on Thursday at a petrol station in the Syrian capital Damascus, opposition activists said.

The petrol station was packed with people queuing for fuel that has become increasingly scarce during the country's 21-month-long civil war, the activists said.

The bombing took place in the Barzeh al-Balad district, whose residents include a mix of majority Sunni Muslims and several other religious and ethnic minorities.

The opposition Revolution leadership Council in Damascus said in a statement: "A booby-trapped car at the site killed several people and injured dozens." There was no immediate indication of who may have been responsible.

An activist who lives in the area said he saw ambulances loading burnt bodies and wounded people with severe burns before he was ordered away by security forces surrounding the station. Tow trucks removed destroyed vehicles, he added.

"The station is usually packed even when it has no fuel. There are lots of people who sleep there overnight, waiting for early morning fuel consignments," said the activist, who did not want to be named.

He said brawls have increased lately at the petrol station between militia loyal to President Bashar al-Assad and ordinary citizens waiting for fuel, but it was not known who carried out the attack.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Michael Roddy)