MAIDUGURI, Nigeria (AP) — Two female suicide bombers killed 13 people at a crowded market and a military checkpoint outside the biggest city in northeast Nigeria, witnesses said Friday. While they also have attacked churches, many more Muslims are among an estimated 13,000 people killed in the 6-year-old Islamic uprising. The latest attacks took place at Malari village, just outside Maiduguri, and began with an explosion from a teenage girl at the market that killed at least 10 people, said security guard Abba Shehu.