At least eight people were killed and scores wounded in twin suicide and car bomb blasts on Saturday in a Damascus suburb that contains Syria's holiest Shi'ite Muslim shrine, state television said.

State media, which flashed the news, did not give further details about the bombings in the Sayeda Zeinab area, where at least three bomb attacks claimed by Islamic State militants have killed and injured scores of people this year.

A Shi'ite religious cleric on the state-run Ikhbariyah TV channel said the car bomb blast was not far from the shrine area in the main al-Taen street.

The UK-based Syrian Observatory for Human Rights said the death toll was at least nine. The heavily garrisoned area is a well known stronghold of Lebanon's powerful Shi'ite Hezbollah group, a major backer of Syrian President Bashar al-Assad.

Thousands of Iraqi and Afghan Shi'ite militia recruits who volunteer to fight against the Sunni rebel groups trying to bring down Assad's government normally come to the area before being sent to frontlines across Syria.

They say they come to Syria to defend the Sayeda Zeinab shrine from radical Sunni extremists.