He met Asif Ali Zardari, the Pakistani president, and General Ashfaq Kayani, the army chief, for talks on regional security, a spokesman for Zardari said.

'Operation successful

Referring to the fighters, a senior government official in Mohmand, Shahidullah Khan, told the Reuters news agency by telephone: "The operation has been successful. Their power has been reduced, we're facing less resistance."

Khan and the paramilitary Mohmand Rifles force said 38 fighters had been killed on Tuesday. The force said 22 fighters had been killed in fighting on Monday.

Khan said there had been no casualties on the government side.

A Pakistani security official said the fighters suffered losses in attacks by "war planes, helicopter gunships and use of artillery and shelling by tanks".

Those killed included two commanders of the Taliban fighters, he said.

Commanders named

"We have confirmation that commander Anwar Sayed and commander Shakirullah were killed in the operation today," a security official said.

Their bases were also destroyed, he said.

He also said that troops demolished or torched at least 27 houses belonging to tribesmen who offered shelter to the fighters.

Five civilians were wounded in the shelling, he said.

A Mohmand Rifles official told AFP on the condition of anonymity: "The operation is going on in Mohmand. The forces have secured a large area in the troubled district and militant strongholds have been destroyed."

The force said two fighters' strongholds had been destroyed and another two were being attacked. Several Taliban commanders had been killed, it said in a release.

Border villages

A spokesman for the Mohmad Rifles said earlier the assault was focused on five border villages controlled by fighters.

Villagers said the soldiers were also using tanks and artillery in the fighting and at least 12 civilians had been wounded in air strikes.

None of the statistics given out by the Pakistani security officials could be confirmed through independent sources.

Last week, more than 600 fighters, many from Afghanistan, attacked a military camp and two checkpoints in Mohmand and six soldiers and 40 fighters were killed, the military said.

Intensified Pakistani efforts against the fighters have led to what some officials call reverse infiltration, with some Taliban coming back into Pakistan to protect their rear bases.

Official released

Separately, Taliban fighters released a senior government official in the South Waziristan region, on the Afghan border to the southwest of Mohmand, after more than a week in captivity, a government official said.

Residents and intelligence officials said that Taliban fighters also shot dead six people and dumped their bodies by a road in the North Waziristan region after accusing them of being US spies.

A note left with the bodies said they were a "gift for Obama, Karzai and Zardari", referring to the new US president and the leaders of Afghanistan and Pakistan.

North Waziristan is a known sanctuary for al-Qaeda and Taliban fighters.