At least 60 militants have been killed after the Pakistani army launched air strikes on two Taleban training camps in north-west Pakistan, the army says.
The operation in the Swat Valley occurred late on Friday shortly after troops found a Chinese engineer alive who had been kidnapped by the Taleban.
The military said efforts were under way to rescue a second Chinese hostage.
There was no confirmation of the attack. Militants have been fighting to impose Sharia law in Swat.
"According to our information, at least 60 Taleban died and many others were wounded during yesterday's operation around Matta town. This is the same area where one Chinese engineer was recovered," the army statement said.
Jet fighters pounded positions of the militants, destroying two of their training camps, military spokesman Major Nasir Ali told the Reuters news agency.
The two Chinese telecommunications engineers and their Pakistani driver were abducted by the Taleban on 29 August in the Dir region, near the border of Afghanistan, where they had been checking an installation.
A Taleban spokesman told the BBC that one of the hostages had escaped. He said the second man also tried to escape but had fallen, hurt his leg, and been recaptured.
Correspondents say the security situation in Swat has been steadily deteriorating since the breakdown in the summer of a peace agreement between the government and the leading militant there, Maulana Fazlullah.
The Swat valley, once Pakistan's most famous tourist destination, has been the scene of an insurgency by his followers since 2007.
Reports said fighting between Taleban fighters and the army was also under way in the region of Bajaur, a militant stronghold which borders Afghanistan.