Afghan officials say a roadside bomb has killed three Afghans and two foreigners in the country's south.
Officials say the victims worked for an American security company (USPI) and were killed on the road linking Kandahar with Herat.
The nationalities of the two foreigners is not clear. The Taleban are being blamed for the attack.
In a separate incident, a suicide bomber blew up himself and his accomplice in the center of Kandahar city Tuesday. There were no other casualties.
The governor of Kandahar province, Asadullah Khalid, blamed the attack on people he considers Taleban militants.
Taleban insurgents have increased attacks in southern Afghanistan in recent months.
U.S.-led forces overthrew the hardline Islamist Taleban regime in late 2001, following the September 11 terrorist attacks in the United States.
Some information for this report was provided by AFP, AP and Reuters.