Suspected US missile strikes killed eight people in northwest Pakistan, where al-Qaida and Taliban leaders are believed hiding, officials and witnesses said. The identities of those killed in the two attacks Monday - the latest in a stepped up American campaign in the lawless region close to the Afghan border - were not immediately known. Meanwhile, the government said an al-Qaida-linked terror group was suspected of helping carry out the September suicide attack on the Marriott Hotel in Islamabad. Interior Ministry chief Rehman Malik's charge against Lashkar-e-Jhangvi was the first time Pakistan has blamed a specific group for the bombing, which killed more than 50 people. Monday's missiles struck about five miles apart just south of Wana, the main town in the South Waziristan tribal area, said local security official Bakht Janan. A house and a vehicle were destroyed in the attacks, which killed four people in each location, he said. Witnesses told The Associated Press that an anti-aircraft gun mounted on a vehicle fired on one of the drones before it launched a missile. The US has carried out more than 30 missile strikes since August in Pakistan's lawless, semiautonomous tribal areas, targeting al-Qaida and Taliban militants blamed for attacks in Afghanistan. While the missile strikes have killed scores of militants, Pakistan has criticized them as an infringement of its sovereignty and says it undermines its own battle against extremism. Most of the missiles are believed launched from unmanned spy planes that take off from Afghanistan. Officials at the US Embassy in Islamabad could not be reached for comment on the missile strikes. Washington rarely confirms or denies the attacks and has pushed Islamabad to crack down on militants in the tribal areas. The US Embassy said in statement that Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff, was in Pakistan on Monday to meet with senior government officials. Mullen arrived from Afghanistan, where he said the US would send up to 30,000 additional troops to the country by summer to fight the resurgent Taliban. Pakistan has arrested three people in the Sept. 20 Marriott truck bombing, but no one has been formally charged. Malik told lawmakers that assailants packed explosives into the truck in Jhang town in Punjab province, south of Islamabad. He said the plot was "assisted" by Lashkar-e-Jhangvi, but gave no more details on its involvement. Lashkar-e-Jhangvi is a Sunni Muslim militant group accused of killing hundreds of minority Shiites across Pakistan. Experts say in recent years it has formed links with al-Qaida. The group has been accused of attacks again Westerners in Karachi and two assassination attempts against former Pakistani President Pervez Musharraf in 2003.