The Iraqi authorities have imposed a curfew on the city of Baquba following a suicide bomb attack near a convoy carrying the provincial governor.
Governor Raad Rasheed was not hurt, but at least one civilian died when the attacker detonated an explosives-packed vest in the Diyala province capital.
Iraqi officials said the curfew would last until Wednesday morning.
Iraqi and US forces have been carrying out a major offensive against insurgents over the past two weeks.
On Monday, the government announced a week-long suspension of military operations in Diyala province to give militants a chance to surrender.
