BAGHDAD (Reuters) - A suicide bomber killed six people near Iraq’s holy city of Kerbala on Monday at the start of a major Shi’ite Muslim ritual, an attack claimed by the hardline Sunni militants of Islamic State.

The bomber blew himself up west of the city where hundreds of thousands of Shi’ites were gathering to mark Arbaeen, which comes at the end of a 40-day mourning period for Imam Hussein, the grandson of the Prophet Mohammad.

Security forces killed five of the bomber’s accomplices before surrounding him in a house where he detonated the device in the rural area of Ain al-Tamr, the ministry added.

Islamic State said in a statement it had planned to target Shi’ites, police and army personnel.

Huge crowds visit the shrines of Hussein and his half-brother Abbas in Kerbala, where they were killed in the 7th century AD, in a revolt against the Umayyad ruler Yazeed.

Islamic State says Shi’ite Muslims are apostates and has regularly attacked their mosques and events.