The Islamic State (Isis) has claimed responsibility for twin bombings in the predominantly Shia Damascus suburb of Sayyida Zeinab which killed at least 20 people. An additional 13 people were injured by a suicide bomber and car bomb on 11 June with the terror groups Amaq news agency confirming the suspicion that the extremists were behind the attack.

The district contains Syrias holiest Shiite Muslim shrine and often foreign Shia fighters would pay homage before going to fight Daesh (Isis) elsewhere in the war-torn country. Sayyida Zeinab is roughly 10km (six miles) south from central Damascus and has been targeted by IS three times already this year killing more than 140 people.

The suburb is a well-known Lebanese Hezbollah stronghold which is a major backer of embattled Syrian President Bashar al-Assad. The area around the shrine was at the centre of fighting in the early days of the Syrian civil war in 2011 but regime troops and Shia militias led by Hezbollah have since secured the site.

The area attracts pilgrims visiting the golden-domed Sayyida Zeinab shrine said to contain the grave of one of the Prophet Muhammads grand-daughters. The split between Shia and Sunni dates from this period, which is why the shrine is at the forefront of the sectarian violence in Syria.

According to Reuters a Shiite religious cleric on state-run Ikhbariyah TV said the car bomb blast was not far from the holy shrine area in al-Teen Street. State TV confirmed the bombings without giving further information.

According to the Sana news agency, the first blast was by an attacker wearing an explosives belt at the entrance of to the suburb. The car bomb attack was detonated in al-Teen Street, not far from the shrine. The UK-based Syrian Observatory for Human Rights (SOHR) said that at least nine died before the AFP said 20 had been killed.

On April 25 this year eight people died when a suicide bomber detonated his vehicle at a military checkpoint in the suburb. Before that, in February, a series of blasts killed at least 83 people and wounding more than 170.

In January 45 people were killed and scores wounded after triple blasts that were quickly claimed by IS.