Pakistani security forces have found no sign of Usama bin Laden (search) hiding in a mountainous region bordering Afghanistan (search) and suspect the terrorist leader may not be there, the top military commander in the area said.

U.S. authorities have long said they believe bin Laden is in the rugged tribal region, but there has been no firm evidence of his whereabouts for three years. Pakistani leaders have gone back and forth on whether they believe the Al Qaeda (search) chief is in their territory.

Lt. Gen. Safdar Hussain, the top commander in northwest Pakistan, said late Tuesday that his forces have scoured the region looking for bin Laden, but with no success.

"Everything is in our view, if Usama bin Laden was there we would know. He cannot hide there. He is not there," Hussain told reporters in Peshawar city.

Pakistan, a key ally of the United States in its war on terror, has arrested more than 600 Al Qaeda suspects, but none of the senior figures have been caught in the border region. They have mostly been nabbed in cities in other parts of the country.

However, Hussain said there are still hundreds of militants, many who are suspected to have ties to Al Qaeda, in the region.

He said that since March, security forces have killed 246 of them, 100 of which were foreigners, and arrested 579. About 170 army and paramilitary troops have also been killed in the crackdown, he said.

"Our war against foreign terrorists will continue ... until we are successful. We will rest after the foreign terrorists are eliminated," he said.

In the latest fighting in the area, five Pakistani soldiers were killed and seven wounded by suspected Islamic militants who attacked a convoy Tuesday, intelligence sources said.

The clash occurred on a dirt road in Spinkargzai village in South Waziristan, near the area where Pakistani commandos last week attacked Al Qaeda-linked kidnappers holding two Chinese.

One of the Chinese hostages died in last Thursday's attack, while five militants — followers of a former Guantanamo Bay prisoner — were killed.