Saudi Arabia was hit early Friday morning by a deadly attack linked to mid-east terrorist group ISIS. At least 10 people were killed when a suicide bomber detonated himself at a Shia mosque in Saudi Arabia's Eastern Province.
An emergency doctor at Qatif Central Hospital said at least 70 were injured, "some very critically".
Witnesses to the scene reported a massive explosion at the Imam Ali mosque in the village of al-Qadeeh, in Qatif governorate.
The attack is the first ISIS terror incident in Saudi Arabia and underscore rising regional tension between Sunni and Shia Muslims.
Nobody has claimed responsibility for the attack at present, however ISIS is strongly suspected by Saudi officials who wished to remain anonymous.
Lebanon's al-Manar television network showed shattered glass and debris sitting next to the tiled pillars inside the mosque, where dozens were praying at the time of the attack.
Bodies covered in bloodied sheets could be seen spread out on the floor, while injured people in bloodstained clothes were whisked away on stretchers.
Qatif hospital, where most of the casualties ended up, has issued an urgent call for blood donations and called in off-duty staff to cope with the high number of casualties.
Saudi Arabia has two enemies who could have perpetrated the attack. It is currently leading a coalition of Arab states in an air campaign against Shia rebels in neighboring Yemen, who could have executed the attack.
The country has also been threatened by the Islamic State (ISIS), which is being targeted by a US-led coalition of which the Saudis are also a part of.
Over 2,000 Saudis are believed to have joined ISIS, with hundreds having returned home forming so called 'sleeper cells'. In response, the Saudi security forces have launched a crackdown in recent months, arresting hundreds of ISIS suspects.