The incident occurred in the Nawa district of Helmand early on Wednesday, the Afghan Defense Ministry said, according to Afghanistan’s Tolo News.
The helicopters had dropped off Afghan commandos during an operation against the Taliban militant group and were carrying wounded Afghan security personnel when they collided “due to technical issues.”
The operation was reportedly still ongoing.
Heavy clashes have been taking place between Afghan security forces and the Taliban in Helmand over the past four days. Thousands of people have been forced to leave their homes for safety.
Sayed Mohammad Amin, the head of Afghanistan’s refugee and repatriation department, said around 5,100 families had been displaced by the fighting, adding that there was an urgent need for food and shelter.
Helmand is one of the most embattled provinces in southern Afghanistan. More than 80 percent of its territory is controlled by the Taliban.
The militants launched a major offensive in the province on Sunday. They have seized military bases and have been closing in on the provincial capital, Lashkargah.
Afghan forces launch counter-assault in Helmand
Afghan security forces launched a counteroffensive in Helmand on Tuesday.
The Helmand governor’s media office said Afghan Special Forces, aided by strikes from the country’s air force, had managed to take back five checkpoints from the Taliban, killing 23 militants.
Heavy clashes erupted between Afghan security forces and the Taliban on the outskirts of Lashkargah on Monday, prompting the local residents of the Nad-e-Ali District to seek refuge elsewhere.
The fighting also resulted in the destruction of a power substation, causing power cuts in Helmand and Kandahar.
A number of telecommunication networks were also shut down.
Jets and helicopters continued to circle Lashkargah through the night on Monday and on Tuesday, attacking Taliban positions.
The United States military also launched airstrikes against Taliban positions in Helmand over the weekend in support of the Afghan security forces. The fighting came despite a “peace” deal between the two sides.