The 13 were among the 58 Pakistanis taken into custody by the US troops from Afghanistan for suspected links to the Taliban and Osama bin Laden’s al-Qaeda.
“As a result of continuous efforts made by Pakistan, the US has freed 13 more Pakistanis from the Guantanamo Bay,” Pakistani interior ministry spokesman Brigadier Javed Cheema said.
The released prisoners are expected to return to Pakistan shortly.
The US had released one Pakistani detainee in November last year, while three more were freed early this year.
Another 41 Pakistani prisoners still remain in the detention centre. Nearly 600 prisoners are being detained in the controversial centre for the past 19 months without trial or any kind of access to legal help.
Most of them had been rounded up in the wake of the US-led military campaign in Afghanistan in November 2001.
Thousands of Pakistanis, many of them young students at religious schools in remote rural areas, went to Afghanistan to support the Taliban against the US-led coalition.
Human rights groups across the world have decried the US-policy to detain prisoners in Guantanamo Bay without any trial.
Adding to the outcry has been the reported appalling conditions in the camp, where the detainees are routinely manacled. Unable to cope with the harsh conditions, some detainees have attempted suicides.
Ex-Taliban commander killed
Meanwhile, unidentified gunmen shot and killed a former Taliban commander in southwestern Pakistan on Thursday.
Officials said Raz Mohammed was killed when he left his home in Quetta’s Pashtunabad neighborhood.
“He was a long-time, brave commander of the Taliban,” Maulana Noor Mohammed, a pro-Taliban member of Pakistan’s federal parliament said.
Both Afghanistan and the US have in the recent past expressed serious concern over Pakistan being used as safe haven by remnants of the Taliban.