Pakistani intelligence officials were investigating reports that a senior al-Qaida figure was among six people killed when missiles hit a building in a village on the border with Afghanistan. Pakistan's army said it had not confirmed that Monday's strike killed al-Qaida operative Abu Khabab al-Masri, described by Washington as an expert who trained terrorists in the use of poisons and explosives. The US offers a US$5 million reward for information leading to his capture. A Pakistani military intelligence official said al-Masri's wife told authorities that her husband died in the attack in South Waziristan. The woman was wounded and hospitalized, he said. Another intelligence official said the strike killed four Egyptians and two Pakistanis. He identified one of the Egyptians as "Abu Khuba," but made clear he was referring to al-Masri. While the U.S. military declined to respond to questions about possible American involvement in the strike, it followed a series of attacks in recent months on militant leaders in Pakistan's tribal belt that are widely believed to have been conducted by the US.