The FBI is to join the investigation into the Najaf mosque bombing after the provincial governor called for US help over the explosion at Iraq’s holiest Shiite Muslim shrine that killed 125 people.

BEATING their chests and calling for revenge, more than 300,000 Muslims began a two-day, 110-mile march yesterday to the holy city of Najaf to mourn a cherished Shi'ite leader assassinated in a car bombing.