Pro-Taliban militants have released 26 of around 240 troops captured over three weeks ago in Pakistan's restive tribal belt bordering Afghanistan, officials said.
The troops have returned to their base in Wana, the main city of the tribal district of South Waziristan, army spokesman Major General Waheed Arshad said.
The release on Friday was secured by tribal mediators, who held a series of negotiations with the rebels from the Mehsud tribe after they surrounded and disarmed seven officers and 233 soldiers on August 30.
"They (the militants) have said they will release the rest of over 200 soldiers only in exchange for their 30 comrades in government custody," negotiator Akhtar Mehsud Gul told the Geo news channel.
The militants have also demanded the complete withdrawal of troops from the tribal areas, which according to Washington and Kabul are safe-havens for Al Qaeda and Taliban warriors launching cross border attacks on international forces in Afghanistan.
Pakistan has deployed more than 90,000 troops to control the insurgents, who have killed over 100 security personnel in tribal areas and neighbouring North-West Frontier Province in retaliatory attacks since military stormed in Islamabad's radical Red Mosque in early July.
The talks for the release of more than 200 hostages will recommence after some response from the government on militant demands, Gul said.