A Yemeni military plane crashed Tuesday into a neighborhood in the country's capital, Sanaa, killing at least nine people and injuring 18, medical and security officials said. The plane crashed during a training exercise, according to Interior Ministry spokesman Mohammed Al-Mawry. It hit two houses in the Al-Qadissiya district, Al-Mawry told The Associated Press. He said the pilot was also killed in the crash. The spokesman did not give a reason for the crash but said military experts were investigating the incident.