Taliban militants have killed 17 Afghan soldiers in one of the single deadliest attacks in recent years. Meanwhile, President Hamid Karzai has welcomed the forthcoming handover of Bagram prison to Afghan authorities.
Authorities in Afghanistan's far-northern province of Badakhstan said local people discovered the bodies on Tuesday night, adding that the soldiers had been abducted on Saturday while guarding a convoy in the province's Warduj area.
But, a Taliban spokesman said the soldiers had been killed during fighting on Saturday and denied that they had been executed.
Officials in the province, which borders China, Pakistan and Tajikistan, said a number of other soldiers had been released after talks conducted by local elders. The Taliban said 11 had been freed in exchange for Taliban fighters.
On Tuesday, the head of US Central Command, General James Mattis had insisted that Afghan forces were increasingly capable and were leading anti-insurgency efforts. NATO combat troops are due to withdraw next year.
"It's now a fact – the Afghans are doing the bulk of the fighting," Mattis told a hearing in Washington.
Bagram handover welcomed
In Kabul on Wednesday Afghan President Hamid Karzai said the handover of the US-run Bagram prison - 50 kilometers (30 miles) north of Kabul - to Afghan officials would take place on Saturday.
He told the opening of a new parliamentary session that he would order the release of "some innocent people," adding that he would oversee such releases "no matter if there is criticism."
Karzai's government has long made control of the prison a precondition for future relations with the United States ahead of the pullout of foreign troops next year.
"After March 9, no Afghans will be in US custody anymore," said Karzai's spokesman Aimal Faizi.
US officials had suggested that some of those released in the past had returned to the battlefield. Rights campaigners have often said Bagram fails to comply with international norms prohibiting detention without charge.
ipj/rc (AFP, dpa)