Two Iraqi policemen have been killed, 14 wounded and at least 36 are missing after an ambush.
The policemen had been travelling from Diwaniya, 180km south of Baghdad, to the capital to collect new vehicles when they were ambushed.
Meanwhile, militants in Iraq killed 12 security men in an ambush near the northern city of Kirkuk.
The group was returning to guard oil facilities in the city when they were ordered from their bus and shot dead.
In the city of Baquba, two Iraqis who worked at a US military base were killed when gunmen fired on their car.
The US military said two of its soldiers have also been killed in Anbar province, west of Baghdad.