Incident occurred in Helmand province where Afghan forces are mounting attacks against Taliban.

A U.S. 'friendly fire' has killed over 10 Afghan policemen in restive Helmand province, local officials confirmed on Saturday.

The incident took place in Grishk district where the Afghan forces are engaged in intense clashes with the Taliban for the past couple of days. The United States Forces-Afghanistan (USFOR-A) has acknowledged the deadly incident.

“During a U.S. supported Afghan National Defense and Security Forces (ANDSF) operation, aerial fires resulted in the deaths of the friendly Afghan forces who were gathered in a compound. We have notified Afghan officials of this incident. An investigation will be conducted to determine the specific circumstances that led to this incident,” it read.

While confirming the incident, Umar Zwak, spokesman for the provincial governor, told Anadolu Agency the Afghan policemen had gathered in a security check post recently reclaimed from the militants when it was hit by the U.S. gunship helicopter.

Grishk police chief, Mohammad Ismail Khpalwak, said over ten members of the police force were killed in the strike.

Earlier on Thursday, Afghan officials confirmed at least 61 Taliban and 11 policemen were killed as clashes erupted in Helmand province after the militants used armored vehicles to storm the security ring and surrounding check posts in Grishk district.

Lying south to the Taliban’s birthplace Kandahar, Helmand remains one of the most insecure provinces in Afghanistan with the militants controlling large swaths of land. Earlier this week, the Afghan National Security Forces (ANSF) backed by the U.S. air power managed to reclaim restive Nawa district in Helmand after over a year when the Taliban overrun it.