Suspected U.S. unmanned aircraft fired six missiles at a vehicle in Pakistan's rugged tribal region Thursday, killing five militants, including a close ally to one of the area's top commanders, Pakistani intelligence officials said.

The attack in the South Waziristan tribal area killed Khan Mohammed, also known as Sathai, deputy leader of a group of militants led by Maulvi Nazir, the officials said.

The officials, who spoke on condition of anonymity because they were not authorized to talk to the media, said Mohammed was also Nazir's cousin. The strike also killed one of Nazir's brothers, Hazrat Omar, they said.

Nazir is one of the most powerful militant commanders in the tribal region and is accused of working with the Taliban and al-Qaida to stage attacks against foreign troops in neighboring Afghanistan.

He is believed to have close relations with Pakistani intelligence and agreed to stay neutral when the military invaded South Waziristan in 2009 to fight the Pakistani Taliban, who have focused their attacks against the Pakistani state.

The militants killed in Thursday's drone strike were riding in a double-cabin pickup truck from Tora Gola village to the nearby area of Azam Warsak when they were hit, said the intelligence officials. Three other people were injured in the attack, they said.

The U.S. refuses to acknowledge the CIA-run drone program in Pakistan publicly, but officials have said privately that the strikes have killed many senior al-Qaida and Taliban commanders.

Also Thursday, a bomb exploded in the main food market in the northwestern Pakistani city of Peshawar, wounding at least 11 people. Police officer Shafqat Malik said three of the victims were in serious condition.

The bomb contained about 6.5 pounds of explosives and was planted in a cooking oil canister. Local TV footage showed damaged shops with pieces of metal and wood littering the ground.

Peshawar is the capital of Khyber Pakhtunkhwa province and has been frequently targeted by the Pakistani Taliban.