Ten police officers have been killed in Afghanistan, by a roadside bomb in the west of the country and during fighting in the south, officials said on Tuesday.
The bomb killed six police guards in Herat province on Tuesday as they travelled to a hydroelectric dam that is under protection from insurgent attack.
The officers were from the Afghan Public Protection Force, a government-run force that provides security for international supply convoys, aid groups and foreign-funded reconstruction sites.
The blast ripped through the vehicle as the men were heading to Obe district in Herat, where India is rebuilding a major hydroelectric dam.
"All six police guards were killed," Sher Agha, the Obe district police chief, told AFP.
There was no claim of responsibility but similar bombs are often blamed on the Taliban, the main militant group waging an insurgency against the government in Kabul.
Four police were also killed in the flashpoint province of Helmand after a Taliban offensive that began on Monday.
Omar Zwak, the provincial spokesman, said a large number of Taliban fighters launched assaults on several security checkpoints.