Rockets rained down on several Old Damascus neighbourhoods Sunday, including one known for its cafes and restaurants, killing at least eight people and wounding 20 others.

The Britain-based Syrian Observatory for Human Rights said the rockets were fired from rebel positions on the outskirts of the capital.

"At least eight people were killed and more than 20 others were wounded when rockets hits several neighbourhoods in Old Damascus," Observatory head Rami Abdel Rahman said.

Syria's state news agency SANA, quoting a police source, denounced a "terrorist attack" that it said killed five people and wounded 16.

SANA said the rockets hit the mostly Christian neighbourhood of Bab Tuma.

The Observatory said rockets also struck Bab al-Salama and Qaymariyeh in Old Damascus.

A restaurant in Qaymariyeh was hit, it said.

An AFP correspondent who went to Bab Tuma said he saw bloodied people running in the streets, calling for help and waiting for ambulances.

A civilian in a pick-up truck ferried several people to hospital, the correspondent said, explaining that ambulances could not enter Bab Tuma because of its narrow alleyways.

A Facebook page dedicated to pinpointing rocket and mortar fire in Damascus posted pictures of destruction at a restaurant, showing overturned chairs and tables and blood on the floor.

Layla al-Jawabrah, 23, said she had been heading towards Bab Tuma when she saw security forces shouting and telling people to run.

"I hid in the entrance of a building... and saw people running. Some were wounded and their clothes were stained with blood," she said.

The rocket attack was the first to target Damascus in months, since a ceasefire brokered by the United States and Russia in February.

But the truce has been violated repeatedly, and Washington and Moscow have tried to reinforce it with temporary or local ceasefires to no avail.

Damascus is mostly controlled by regime forces, but rebels hold districts on its outskirts and positions in the countryside.

The capital has been largely spared the deadly violence that has spiralled and engulfed Syria since the conflict erupted in 2011 with peaceful anti-government protests.

More than 280,000 people have been killed over the past five years and millions displaced.

Source: AFP