A bomb attack outside a Shia mosque in Saudi Arabia has killed at least four people.

The Saudi branch of Islamic State in Iraq and Syria (Isis), Wilayat Najd have claimed the attack.

The attack took place outside a Shia mosque in the village of Anoud in Damman in the Eastern Province of Saudi Arabia during Friday prayers.

The Saudi Press Agency reports that security men approached a suspicious car outside the mosque. A man wearing women’s clothes then activated a suicide belt, killing himself and three others. Four more were reported injured.

The bombing comes a week after an attack on another Shia mosque, which killed 24. Wilayat Najd also claimed that attack.

Oil prices rose marginally to just over $60 a barrel following the attack.

Saudi Arabia is also facing instability on its Iraqi and Yemeni borders. Isis has recently gained territory in Iraq, including Ramadi. In Yemen, Saudi Arabia is leading an Arab Sunni coalition against the Shia Houthi movement, which has taken over much of the country.

Heightened anti-Iran rhetoric since the start of the military campaign is deepening sectarian tensions in Saudi Arabia.

The attack may increase tensions in the Eastern Province, which is home to the majority of Saudi Arabia’s Shia population.