The Pakistan army has reportedly killed up to 50 fighters in a battle near the border with Afghanistan.

The army said on Sunday that it inflicted heavy casualties when about 300 fighters stormed a military base in Lhada on Wednesday and Thursday, the Associated Press reported.

The military used small-arms fire and artillery to dissuade the attack.

The clashes are the bloodiest in weeks in the region, where high-ranking Taliban and al-Qaeda leaders are thought to be hiding and planning operations.

An army statement said: "Intelligence resources revealed the killing of [between] 40 and 50 militants."

Officials also said that two Uzbek "extremist fighters" were shot and killed by pro-government tribesman.

The deaths occurred early on Sunday in South Waziristan.

The Pakistani government has attempted to encourage tribes to fight against what they see as undesirable groups - many of whom harbour foreign fighters.

The border with Afghanistan became a scene of constant battles after the September 11, 2001, attacks and Pakistan's consequent support for America's "war on terror".

PHOTO CAPTION

Pakistani tribesman fighter.

Al-Jazeera