ROBERT SIEGEL, HOST:
For the first time, the self-proclaimed Islamic State is claiming responsibility for an attack in Saudi Arabia. At least 21 Shiite Muslims were killed today in a bombing on a mosque. It heightens concerns about attacks on Shia in the predominantly Sunni Muslim kingdom. NPR's Leila Fadel reports.
LEILA FADEL, BYLINE: Witnesses said the bomber ran into a Shiite mosque and detonated a device he was wearing under his clothes. At the time, worshipers were performing their Friday prayers. Pictures from inside the mosque show dead bodies, rubble and shattered glass. After the blast, people gathered in the street in protest.
(SOUNDBITE OF PROTEST)
UNIDENTIFIED MAN #1: (Chanting in foreign language).
DEMONSTRATORS: (Chanting in foreign language).
UNIDENTIFIED MAN #1: (Chanting in foreign language).
FADEL: We only kneel for God, the demonstrators chanted in a video posted online - no to terrorism. ISIS claimed responsibility in an online statement from a branch they dub the Nejd State, a reference to the central region of Saudi Arabia. They called Shias impure and declared them polytheists. They promise that dark days lie ahead for Shia and that ISIS would drive all so-called polytheists out of the Arabian Peninsula.
This is the second attack on Shia in Saudi Arabia since November, when seven were gunned down. The government blamed the attack on ISIS, which has also called for attacks against the monarchy. Saudi Shia say rhetoric and prejudice against them has increased since Saudi began airstrikes in Yemen against Houthis, who they accuse of being a proxy for Shiite Iran. Leila Fadel, NPR News, Cairo. Transcript provided by NPR, Copyright NPR.