Gunmen killed an aide to Iraq’s most influential Shiite cleric and two bodyguards in a drive-by shooting outside a Baghdad mosque today – an attack likely to stoke tensions between the Shiite majority and the Sunni minority, officials said.

A suicide bomber detonated his car near a checkpoint outside the offices of Iraqi Prime Minister Ibrahim al-Jaafari’s Islamic Dawa Party today, killing one guard and injuring at least one more.