Syria Damascus
Representational: A child inspects damage, after what activists said were seven air-strikes by forces loyal to Syria's President Bashar al-Assad, in Duma in Eastern Al-Ghouta, near Damascus, February 2, 2015.Reuters

At least eight people were wounded in a rocket attack on residential areas of Damascus on Thursday, state news agency SANA said, in what appeared to the second heavy bombardment by insurgent group Islam Army in less than two weeks.

Shells thought to be fired from the east of the capital could be heard exploding in the city, a witness said, and local media reported that Islam Army, a group based in the eastern Ghouta region on the outskirts of the city, was behind the attack.

SANA said it was a "terrorist" attack, without giving further details. Islam Army's leader said on Tuesday that his group would target the Syrian capital.

The same group struck the capital with at least 38 rockets on Jan 25, killing seven people, a monitoring group said, in one of the heaviest attacks on Damascus in over a year.

A witness in Damascus on Thursday heard more than 30 bombardments in quick succession. Local radio Sham FM said the projectiles had hit at least five areas of the capital, including the historic Old City. People posted images on social media said to show plumes of smoke rising above the city.

A message on a Twitter account thought to belong to Islam Army's leader Zahran Alloush said the attack was a "taste" of what the Syrian military had done to Ghouta.

He described Damascus as a "military zone" in a statement earlier this week and said his group would respond to Syrian air force strikes on Ghouta.