A policeman in Kandahar Province's Spin Boldak district, Mohammad Asif Khan, said the attack occurred on a main highway in the district, where the company was providing security for road construction projects.
SUBSCRIBE For regular news and analysis on Afghanistan by e-mail, subscribe to "RFE/RL Afghanistan Report."
Three security guards were killed, along with their driver.
Meanwhile, reports say a explosion rocked the center of the capital Kabul today.
It is not immediately clear what caused the blast, or whether there were casualties.
(AP, AFP)
RFE/RL Afghanistan Report
RFE/RL Afghanistan Report
SUBSCRIBE For regular news and analysis on Afghanistan by e-mail, subscribe to "RFE/RL Afghanistan Report."
