At least 40 militants were killed on Thursday in an artillery and air attack in Pakistan's restive northwestern tribal district of Orakzai near the Afghan border, a security official said.
The strike by Pakistani troops occurred in the Mamozai area of the district, where security forces have stepped up ground and air attacks against Taliban militants in recent days, a security official said on the condition of anonymity.
Pakistani forces are using heavy artillery and are backed by jet fighters and helicopter gunships in the latest offensive targeting militant hideouts.
Thursday's death toll could not be verified independently because no media or aid workers are present there.
Similar fighting killed at least 21 militants in the district's Sultan Zai area Wednesday.
Orakzai emerged as a trouble spot and a hotbed of Taliban militants after they were defeated in South Waziristan and Bajour tribal districts.
Most of the militants fled to Orakzai after they were pushed out of South Waziristan in a successful government assault launched in mid-October and the government's announcement of victory in Bajour last month.
Pakistan, long accused of being soft on the militants, has been praised by the US for these offensives.
The latest assault coincided with a strategic dialogue being held this week in Washington between the US and Pakistan, which is trying to persuade the US to provide it broader military and economic support in its fight against the militants.
In Wednesday's opening session of the dialogue, US Secretary of State Hillary Clinton said she recognised the sacrifices of Pakistani security forces and people in efforts to eliminate terrorism.