Four policemen have been killed by a roadside bomb in Badghis province, which is located 555 kilometers (344 kilometers) northwest of the Afghan capital Kabul.
Provincial governor's spokesman Sharafudin Majedi said that a police pick-up truck hit a roadside bomb planted by militants in the Qadis district of the province on Saturday.
“Unfortunately, all four policemen onboard were killed,” he added.
Roadside bombs and improvised explosive devices (IEDs) are by far the most lethal weapon Taliban militants use against Afghan forces, foreign troops, and civilians.
The homemade explosives accounted for about half of the 1,500 civilian deaths in the first six months of last year, according to the United Nations.
Insecurity continues to rise across Afghanistan despite the presence of about 130,000 US-led forces in the war-torn country.
The United Nations announced on February 4 that 2011 was the deadliest year on record for Afghan civilians. The death toll rose eight percent compared to the year before and was roughly double the figure for 2007.
Overall, 3,021 civilians died in violence related to the war and 4,507 were injured in 2011. Of the deaths, the UN attributed 77 percent to militant attacks and 14 percent to US-led foreign troops and Afghan forces. Nine percent of the cases were classified as unknown.