PESHAWAR: At least three soldiers and up to 34 militants were killed on Thursday in a gunbattle in Pakistan's restive tribal district of Khyber along the Afghan border, officials said.

The death toll was announced shortly before US Secretary of State Hillary Clinton was expected in Pakistan for crunch talks aimed at ramping up pressure on Islamabad to do more to eliminate Taliban safe havens on the Afghan border.

The fighting erupted when Pakistan's paramilitary Frontier Corps (FC) launched a search operation in the Malik din Khel area of Khyber.

The strategically important Khyber district lies between Peshawar and Afghanistan and is the main route for Nato supplies in Afghanistan.

Mutahir Zeb, the top administrative official of Khyber, said militants from Lashkar-e-Islam (army of Islam) were involved.

“At least 34 militants and three soldiers were killed during an encounter,” a paramilitary statement said. There was no immediate independent confirmation of the death toll as the area is off-limits to journalists and aid workers.

“Security forces responded effectively and have cleared the area of militants,” it said.

Zeb had said earlier that four soldiers had been killed.

Lashkar-e-Islam is the most active militant group in Khyber and led by feared warlord Mangal Bagh. It has loose ideological ties to the Taliban, but operates independently.

Nearly 4,700 people have been killed across Pakistan in attacks blamed on Taliban and al Qaeda-linked militants based in the northwestern tribal belt since government troops stormed a radical mosque in Islamabad in 2007.

Around 3,000 Pakistani soldiers have also lost their lives in attacks since 2001, when the country joined the “war on terror”.