A missile strike killed four people in a Pakistani border region considered a stronghold of Taliban and al-Qaida militants, witnesses and officials said. One official suggested the missiles were launched from Afghan territory just four kilometers away. The US military and NATO in Afghanistan denied involvement. The projectiles hit Saidgi, a village in the North Waziristan region, already targeted in operations against militants last year. A senior military official in the capital, Islamabad, said the dead and wounded were making bombs and had accidentally caused an explosion. But two local intelligence officials said it was a missile attack, and a government official said the projectiles were apparently fired from Afghanistan. "We don't have any information that we were participants in" the incident, said Maj. William Mitchell, a spokesman for the US-led coalition. Lt. Col. Angela Billings, spokeswoman for the separate NATO force, said its troops were not involved.