Suspected militants have released 50 people kidnapped on Saturday in Pakistan's restive northwest, a government official said on Sunday.
Suspected militants dressed as policemen kidnapped at least 60 people in two incidents in the ethnic Pashtun tribal region of Kurram, where government forces have recently stepped up an anti-militant operation.
Negotiations involving tribal elders were underway for the release of the remaining 10 hostages, believed to be employees of the state power company, regional government official Mumtaz Khan told Reuters.
"Militants seem reluctant to free them because they are government employees but we are making all our efforts and we have engaged tribal elders in the process," said Khan.
Pakistani government officials have accused Pakistani Taliban militants of carrying out kidnappings after coming under pressure from security crackdowns in Kurrum and other areas.
Taliban officials were not immediately available for comment.
Some kidnappings in the region were believed to have been carried out by tribes.
Hameedullah Khan, a tribal elder, had a different account of what happened with the hostages, saying militants released 40, while 10 escaped. He was optimistic those still being held would be freed.
"The 10 men do not have identity cards so the Taliban are just holding them to verify their identity. It's not a big deal," Khan said.
In a video message last week, Pakistan's Taliban warned America it will soon "burn" while calling for Pakistan's rulers to be overthrown for following "America's agenda".
The United States is convinced Pakistani Taliban militants allied with al Qaeda and operating out of northwestern Pakistani border regions were behind an attempted car-bomb attack in New York's Times Square on May 1.
The Pakistani Taliban claimed responsibility for the attempted bombing. If confirmed, it would be the first time their members were involved in an attempted attack in the West.
Pakistan has mounted military offensives against militants in their strongholds in the northwest over the past year, largely clearing several areas, killing hundreds of militants and destroying their bases, according to government officials.
Militants have shown resilience and carried out a wave of suicide and bomb attacks, mainly in the northwest, killing hundreds of people.
Pakistani fighter jets bombed two Taliban hideouts on Sunday in Orakzai region, near Kurram, killing 13 militants, a government official said.
There was no independent confirmation of those figures. Taliban militants often dismiss official casualty figures.