A rocket was fired Wednesday morning at the building where U.S. forces searching for Al Qaeda members in Pakistan's wild tribal regions were sleeping, a local Pakistani official said. The rocket missed and no one was injured.

The rocket was fired about 3 a.m. at a vocational training institute in Miranshah, about 9 miles from the Afghanistan border in rugged northwestern Pakistan, an official in Miranshah said on condition of anonymity.

It was apparently fired from a hilly area to the north -- on the Afghan side of the border, he said.

Local people said the rocket missed the institute and hit the wall outside another college about 300 yards away, damaging a wall and windows. No one was hurt because the building was empty, the official said.

At the U.S. Central Command in Florida, Air Force Lt. Col. Martin Compton said officials were unaware of the incident and that he had no information that American military were in the building.

It was not known who fired the rocket, but area residents found pamphlets from a previously unknown group called Mujahedeen of North Waziristan -- the tribal region of which Miranshah is the center.

The pamphlet warned area Muslims to "wake up because the hypocrite rulers have challenged the faith and Islamic honor ... by bringing American commandos to Miranshah."

It warned Muslims faced "disgrace and trouble" unless they "stand up against the army of Jews and Christians," and said the murder of Pakistani troops and officials assisting the Americans was also "justified."

The pamphlet was dropped around town overnight, said Haji Mujbaba said by telephone from Miransha. "This morning people found it in different places in the market areas," he said.

The number of U.S. soldiers staying in the building was unknown.

Both U.S. and Pakistani officials have confirmed that a small U.S. force is operating with Pakistani troops in the wild tribal region, which borders Afghanistan. The area is the traditional stronghold for Usama bin Laden, the Saudi-born fugitive who heads Al Qaeda.

The Pakistani army treads lightly in the tribal regions, whose deeply conservative and fiercely independent inhabitants swear little allegiance to anyone but their tribal elders and laws laid out by tradition and strict adherence to the tenets of Islam.

A raid last weekend on a religious school resulted in no arrests, but enraged local religious leaders, who condemned the presence of Americans as an insult to their sacred sites.

"We will not let American forces operate in our areas," Maulvi Abdul Hafeez, a prominent cleric in Mir Ali, about 200 miles southwest of Peshawar, told The Associated Press by phone on Saturday.

Until recently, the U.S. military presence in Pakistan was mainly confined to air bases and other such facilities. Clashes have been rare despite a vocal minority of hardline Islamic groups that still support Afghanistan's Taliban.

Last October, the Pentagon said a U.S. helicopter that had picked up an Army Black Hawk helicopter that had crashed hours earlier in Pakistan came under hostile fire while refueling at a Pakistani airfield. No details were released, but a Pentagon spokeswoman said there were no U.S. casualties.

In the first two months of the war on terror there were at least two attacks on U.S. military stationed at the air force base in Jacobabad, in southern Sindh province. It is one of three airbases being used by the U.S. military in Pakistan.

Across the border from the tribal regions in eastern Afghanistan, where U.S.-led special forces have been running down remnants of Al Qaeda and Taliban forces, such attacks are more frequent.

Just Monday, Australian military officials said their special forces opened fire after coming under mortar and rocket-propelled grenade fire, killing or wounding two of the attackers.

Last Thursday, attackers fired a rocket near a small U.S. outpost in the Afghan city of Khost, about 30 miles northwest of Miranshah. No injuries were reported.