A suicide bomber blew himself up inside a bus travelling from the northern Iraqi city of Mosul to Syria on Tuesday, killing at least nine passengers, an Iraqi army officer told AFP.
Iraqi army Lieutenant Colonel Jalal Dosky said the attack took place near a checkpoint in an area called Smeirath, 80 kilometres (50 miles) north of Mosul, the officials said.
A senior Iraqi police officer in Mosul also confirmed the attack.
The US military said in a statement that they suspected that an Al-Qaeda in Iraq (AQI) member carried out the attack but said eight people were killed in the bombing.
"During a stop at a routine checkpoint, the Iraqi army searched passengers for their identification cards. The suspected AQI suicide bomber exited the bus and then detonated the bomb," the military said.
The US military toll said eight people were killed and eight others wounded.
"The Iraqi army were doing their job, and reacted to the incident in a professional manner," it said.
Meanwhile a group of armed men set up a fake checkpoint north of Iraq's restive town of Baquba and kidnapped 21 civilians travelling in two minibuses yesterday, police said.
Police Lieutenant Colonel Najim al-Sumaidaie from Baquba told AFP the checkpoint was set up in an area called Al-Adaim, 60km north of Baquba in the Diyala province, northeast of Baghdad.
"At about 10:00 am (0700 GMT) several armed men stopped a minibus carrying 11 men and three women at the checkpoint. They released the women but abducted the men," Sumaidaie said.
He said minutes later another minibus was stopped by the kidnappers and 10 men travelling in it were also abducted.
"All the 21 men were taken away in the same minibuses," Sumaidaie said.
He said the two buses had come from the northern oil city of Kirkuk and were on way to Baghdad passing through the treacherous terrain of Diyala.