Three US soldiers were killed in a "complex attack" involving a roadside bomb and small arms fire north of Baghdad, the US military said Wednesday. The Multi-National Division - North soldiers were attacked Tuesday while conducting operations in Salahuddin province north of Baghdad, the military said in a statement. The military raised the death toll to three after one soldier died Wednesday of wounds sustained in the attack. A fourth soldier was wounded, the military said. The soldiers' names were withheld pending family notification.