KABUL, Afghanistan -- Mistaking each other for the enemy, Afghan police fired four dozen grenades and US-led coalition troops fought back with helicopter gunships in a fierce battle that left eight officers dead before dawn yesterday, officials said.
The deadly lapse in communication underscored the wide gaps -- and apparent mistrust -- between US and Afghan security forces.
President Hamid Karzai's office called the deaths "a tragic incident" caused by a lack of cooperation and communication.
US officials have said they are wary of telling Afghan forces about nighttime raids by US Special Forces, the kind of operation apparently being conducted early yesterday, out of fear the target might be tipped off.
The US-led coalition said a joint coalition-Afghan force on a mission against a suspected Taliban safehouse was fired on first and responded with its own weapons, then summoned air support. It said no US casualties were reported.
A presidential spokesman also said police initiated the shooting, but officers at the isolated post on a barren stretch of desert in the eastern province of Nangarhar said US troops fired first.
"The Americans came close to our checkpoint with the lights of their vehicles off," said Esanullah, commander of the roadblock. "We shouted at them to stop, but they didn't, and they opened fire on us." He said eight policemen were killed and four wounded.
Officers at the post fired 49 of their 50 rocket-propelled grenades and called for assistance from reserve police during the three-hour firefight, said Esanullah, who goes by one name.
Karzai's spokesman, Karim Rahimi, said the incident underscored why the president has repeatedly called for increased cooperation between Afghan and international troops, which would help solve the problem of civilian casualties in Afghanistan.
"The police forces were not aware of the coalition's operation," Rahimi said. "The police checkpoint in the area thought that they were the enemy, so police opened fire on the coalition, and then the coalition thought that the enemies were firing on them, so they returned fire back."
Major Chris Belcher, a coalition spokesman, said the troops were fired at by small arms and rocket-propelled grenades from two sides while on the way to conduct an operation against the suspected Taliban safehouse.
"Afghan and coalition forces took incoming fire and they responded to it," Belcher said.
Mistaken killings by international troops has been a problem in Afghanistan, and nighttime raids by US Special Forces in particular have been criticized for causing civilian casualties.
Recent incidents prompted the upper house of Afghanistan's parliament to pass a resolution last month that would prohibit foreign soldiers from launching military action unless they are attacked first or have consulted Afghan officials. The resolution hasn't been acted on by the lower house.
NATO officials have said they are working on ways to increase involvement of Afghan troops on missions to cut down on mistaken killings, but those mechanisms apparently are not yet in place.
The US-led coalition conducts counterterrorism missions, while the NATO force in Afghanistan, which includes some American troops, is responsible for counterinsurgency operations.
The eight police deaths in Nangarhar occurred in the same province where US Marines killed 19 civilians and wounded 50 in March while speeding away from the site of a suicide bomb attack, casualties that sparked angry protests and denunciations of the US presence there.
A US military commander later determined the Marines used excessive force.