A family member of a slain victim mourns after arriving at the Imam Ali mosque, the site of a suicide bomb attack, in the village of al-Qadeeh in the eastern province of Gatif, Saudi Arabia, May 22, 2015. A suicide bomber blew himself up at the Shi'ite mosque in eastern Saudi Arabia during Friday prayers, leaving many dead or wounded. REUTERS/Stringer

Family members of victims and well wishers are seen after a suicide bomb attack at the Imam Ali mosque in the village of al-Qadeeh in the eastern province of Gatif May 22, 2015. REUTERS/Stringer

Family members of victims and well wishers are seen after a suicide bomb attack at the Imam Ali mosque in the village of al-Qadeeh in the eastern province of Gatif May 22, 2015. REUTERS/Stringer

Family members of victims and well wishers are seen after a suicide bomb attack at the Imam Ali mosque in the village of al-Qadeeh in the eastern province of Gatif May 22, 2015. REUTERS/Stringer

Family members of victims and well wishers are seen after a suicide bomb attack at the Imam Ali mosque in the village of al-Qadeeh in the eastern province of Gatif May 22, 2015. REUTERS/Stringer