A suspected US missile strike on a tribal area in northwest Pakistan killed at least eight militants on Monday, officials said. Two missiles struck the villages of Karikot and Shin Warsak in South Waziristan on the border with Afghanistan, they said. It was not immediately clear if any senior Taliban or Al-Qaeda operatives were killed in the strikes, which took place just minutes apart, a senior security official said. "Two vehicles fitted with guns were destroyed in two separate attacks that also damaged a house," the official said, adding that the eight people killed were all inside the vehicles. The strikes caused huge fires in both villages, sending panicked residents running into the streets, he said. A series of recent strikes against suspected Al-Qaeda and Taliban hideouts in Pakistan's tribal areas bordering Afghanistan -- all blamed on unmanned CIA drones -- have raised tensions between Washington and Islamabad. The strikes have continued despite a warning by Taliban militants based in tribal territory last month that any more would lead to reprisal attacks across Pakistan.