The special forces, operating out of neighboring Kandahar province, attacked a private home in the Nawzad district, according to NATO's Resolute Support mission in the capital, Kabul.

NATO supported the mission as part of its train, advise and assist mission, but gave no specifics as to its role in the raid.

"Afghan Special Forces liberated over 60 prisoners from an illegally run Taliban prison... during the cover of darkness via helicopter assault," NATO said in a statement. "The liberated prisoners were safely transported to Kandahar where they were turned over to ... Afghan authorities."

The prisoners were reportedly a mix of Afghan security forces and civilians, although the governor of Helmand province, Hayatullah Hayat, said they are still determining who the captives were.

"We are still investigating as to who these people are and how long they were kept there," he said.

Two Taliban killed, more injured

At least two Taliban fighters were killed in the raid and more were injured, although it is unclear if the number injured were few or many. No government troops or prisoners were injured in the raid.

The prison was under the control of Mullah Manan, the Taliban's shadow governor for Helmand. But Manan was not captured during the raid, according to Defense Ministry spokesman Mohammad Radmanish.

The Taliban appear to be rejuvenated, since the withdrawal of virtually all US troops in 2014. Last month the rebel fighters struck with deadly force in the heart of Kabul, killing 64 people in what appeared to be the Taliban's deadliest assault since 2001.

Afghan President Ashraf Ghani responded sharply to the attack, threatening diplomatic reprisals against Pakistan if it refuses to take action against insurgent havens on its soil.

Watch video 01:53 Share Harvesting the world's illegal drugs Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/1IWfB Harvesting opium in Afghanistan

The latest Afghan government raid on a Taliban-run prison is the fourth of its kind in the past six months, which have freed more than 150 prisoners.

The Taliban's spring offensive is expected to be the bloodiest in 15 years. But there is a current lull in the fighting because many insurgent fighters have returned to the fields to harvest a bumper opium crop.

But the harvest will wind down in the coming days, and then fighting is expected to intensify.

Helmand province retained its title as leader in growth of opium, which is used to produce heroin, according to Brig. Gen. Charles Cleveland, a senior spokesman for US forces in Afghanistan.

"There is a concern," Cleveland said, "that with this very good poppy crop that they had this year, it is going to result in the Taliban being able to turn that into money for their efforts."

bik/sms (Reuters, AFP, AP, dpa)