Four Shiite Huthis were killed in a suicide bombing during a religious gathering in the Yemini capital of Sanaa today, according to the Yemen Observer.
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Security officials told the Observer seven other people were wounded in the attack, which the Associated Press said was a rocket-propelled grenade aimed at a crowd of worshippers.
Shiites worldwide are marking Ashoura with elaborate public rituals mourning the death of Imam Hussein bin Ali, Prophet Muhammad's cousin and son-in-law, whom Shiites believe is his rightful successor in a dispute that has divided the Islamic world. Today's events signal the start of a 10-day grieving period.
This is Yemen's first Ashoura following the overthrow of longtime leader President Ali Abdullah Saleh, an uprising in which Huthis are believed to have played a critical role.
Huthis are followers of revivalist Zaydism, a Shiite offshoot, and take their name from their leader Husayn al-Huthi, who was killed by the government in 2004, according to this report on the group from West Point military academy.
The group has come in conflict with extreme Salafis over the past several months, leading to public confrontations that have killed dozens, reported Agence-France Press.