A suspected suicide bomber today blew up a Shia mosque in eastern Saudi Arabia and killed at least 10 people in an attack that has been since been claimed by a Saudi branch of the Islamic State (IS) on Twitter.

One witness told Reuters of a huge explosion at the Imam Ali mosque in the village of al-Qadeeh in Qatif province on Friday morning. A doctor at Qatif Central Hospital told the BBC that 10 people had been killed, and at least 70 injured, some badly.

The attack took place during Friday prayers where more than 150 worshippers were in attendance. Gruesome pictures and video have been emerging on social media purporting to show body parts, corpses covered in sheets laid on the floor of the mosque, and victims being removed on stretchers.

Saudi Arabians predominantly follow the Sunni branch of Islam but it also has a Shia population of 2.7 million, making up between 10-15 percent of the country, who are largely concentrated in the east, including in Qatif province. The region has played host to low-level protests from the Shia population demanding greater rights and recognition.

Firas Abi Ali, a senior manager in MENA country risk for IHS, told VICE News: "This would serve the Islamic State's agenda of creating greater Sunni-Shia polarization, in the hope of forcing the Sunni community to rally behind the group."

He continued: "I think that it is part of an ongoing campaign that will continue. It would force the security forces to dedicate more resources to protect Shia areas. It would then continue with its other tactics like attacks against foreigners, assassinations, and attacks against security forces elsewhere. The idea would be to force the security forces to spread themselves too thin, in order to increase operational freedom."

Saudi Arabia has recently received threats from IS, and the country is also leading a coalition of nations carrying out airstrikes against Houthi rebels in neighboring Yemen.

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Witnesses say at least 5 dead, 20 injured after suicide attack during Friday prayers on mosque in Saudi's Qatif. — Rori Donaghy (@roridonaghy86)May 22, 2015

Images circulating of a suicide bomb attack on a mosque in Qatif in Saudi Arabia — Ala'a Shehabi (@alaashehabi)May 22, 2015

Today's mosque bombing in Qatif is the second attack on a Shiite place of worship in Saudi Arabia after the Dalwah attack last November. — Ahmed Al Omran (@ahmed)May 22, 2015