MIR ALI: An apparent U.S. missile attack destroyed a suspected militant compound in northwestern Pakistan on Tuesday, killing at least nine people, intelligence officials said.

It was not immediately clear who was targeted in the strike, in the Datta Khel region of North Waziristan, said the two officials on condition of anonymity because they were not authorized to talk to the media. An unknown number of people were injured.

The area is the home of Hafiz Gul Bahadur, a powerful warlord whose fighters are battling U.S. and NATO forces in Afghanistan.

The CIA has stepped up missile strikes on militant positions in Pakistan's tribal regions since December, when a suicide bomber killed seven CIA employees in neighboring Afghanistan.

Pakistan publicly criticizes the U.S. missile attacks, saying they violate its sovereignty and fuel more anti-Americanism among the population, but Islamabad is widely believed to be sharing intelligence with the Americans on at least some of the strikes.

Washington refuses to publicly discuss the program, which uses unmanned drones, but Pakistani intelligence and government officials say privately the attacks have killed several senior al-Qaida and Taliban commanders in recent years.

Meanwhile, in the eastern Pakistani city of Lahore, police on Tuesday uncovered the second major weapons cache in as many days. Police, searching a fruit market warehouse, found 4,400 pounds (2,000 kilograms) of explosives, three suicide jackets and four machine guns.

A day earlier, police had discovered a weapons stash that included suicide jackets and more than 3,300 pounds (1,500 kilograms) of explosives. They were hidden inside an unused shop elsewhere in the city.

Lahore has been battered by a string of explosions in recent days. On Friday, two suicide bombers targeting soldiers on patrol killed 55 people and injured about 100 more in coordinated explosions.

Associated Press writer Babar Dogar contributed to this report from Lahore.