At least 28 Pakistani Taliban fighters have been killed in clashes with the Pakistani military in the northwestern tribal region of Orakzai, army officials say.
The fighting, which began on Wednesday after Taliban fighters attacked a security checkpoint in the densely forested Dobbari area in Orakzai, also left two Pakistani soldiers dead.
The security forces used tanks to repel the attackers, killing at least 28 of them and wounding 21, Nauman Khan, a Pakistani government official in the region, said.
"About 200 militants with rocket-propelled grenades and other weapons attacked the checkpost, prompting a fierce response from the security forces," Khan told the Reuters news agency.
But Al Jazeera's Hameedullah Khan, reporting from Pakistan, said that according to sources on the ground, at least 55 Taliban fighters were killed in the fighting.
Violence has risen in Orakzai since the army drove the Taliban from its strongholds in South Waziristan, Swat and Bajaur.
Wednesday's attack came nearly a week after the US said it had evidence the Pakistani Taliban was behind the attempted car bombing in New York's Times Square.
Faisal Shazhad, a Pakistani-born US citizen, has been charged with the attempted bombing.
He has admitted to receiving bomb-making training in the Pakistani region of Waziristan, US prosecutors say.
Pakistan joined the US-led global campaign against "terror" in the days after the September 11, 2001, attacks on the United States.
The army launched an offensive in South Waziristan last year to clear the volatile area of Taliban and al-Qaeda fighters.
In recent weeks, the army has turned its attention to the Orakzai and Khyber regions, where many fighters are believed to have taken refuge from the earlier offensives.
Despite losing ground, Taliban fighters have shown the ability to bounce back and have carried out a wave of bomb attacks, killing hundreds of people, mainly in the northwest.
A roadside bomb killed 12 people, including three policemen, in the northwestern town of Dera Ismail Khan on Tuesday.
Pakistani action against Taliban and al-Qaeda fighters along the Afghan border is seen as crucial for US efforts to bring stability to Afghanistan.