Pakistani troops killed 43 suspected militants and destroyed one of their bases in an ongoing operation in the northwestern Khyber tribal region, authorities said Saturday.

Militants frequently attack trucks along the famed Khyber Pass, one of the main routes used to ferry supplies to NATO and U.S. forces in neighboring Afghanistan.

The Taliban-affiliated group Lashkar-e-Islam has been a main target of the latest government offensive, which authorities say has killed scores of alleged militants.

The paramilitary Frontier Corps announced the latest deaths in a written statement.

"An important markaz (headquarters) of Lashkar-e-Islam being used as the hide-out and main training center was also destroyed in the action," the statement said.

The remote region is largely off-limits to journalists, making it difficult to verify the information independently.

The operation was launched late last month after a suicide bombing at a border checkpoint killed 19 police.

The top government official in Khyber, Tariq Hayat, said the operation would continue until all the militants were flushed out from the region.

Pakistan is under intense U.S. pressure to crack down on militants close to the Afghan border, especially the lawless tribal belt where Al Qaeda leader Usama bin Laden is suspected to be hiding.

The U.S. believes militants use Pakistan's tribal areas and other troubled parts of the northwest as safe havens from which to plan attacks on Western troops across the frontier.

Also Saturday, lawyers said a Pakistani anti-terrorism court resumed pretrial proceedings against five suspects in last year's attacks on the Indian city of Mumbai that killed 166 people.

The hearings are being held behind closed doors at a high-security prison in Rawalpindi and Pakistani authorities have released very few details on the proceedings.

Government prosecutor Malik Rab Nawaz and a defense lawyer, Shahbaz Rajput, confirmed in phone interviews Saturday that the hearings had resumed but said little else because the court has ordered them to avoid discussing the case with the media.

Rajput said he has asked that the case be opened to the public.