Kabul, Afghanistan (CNN) -- NATO authorities said they haven't found evidence to conclude that coalition helicopters were responsible for the deaths of three Afghan police officers last week in northern Afghanistan.
Initially, it was thought that a NATO International Security Assistance Force air weapons team caused the deaths, but a joint incident assessment team determined that the evidence doesn't bear out that claim. The incident occurred in Jowzjan province on August 21.
The team, made up of Afghan government and ISAF officials, traveled to Mazar-e-Sharif, where they interviewed people involved in the incident and reviewed tapes from the helicopters.
The team said the fighting started "several hours before the helicopters arrived" and "lasted several hours after." That made it possible that casualties came from other small arms or indirect fire before or after the choppers were in the area.
"In their report, the team determined the one Hellfire missile and 80 rounds of 30mm fire impacted a positively-identified insurgent firing position. The review of gun-tape footage clearly indicates the fire provided by the air weapons team impacted a hilltop where enemy activity was present," ISAF said.
An Afghan military official concluded that no coalition fire struck the inside of a compound where Afghan forces were located.