MAIDUGURI, Nigeria (AP) — Armed extremists in northeastern Nigeria killed dozens of people earlier this week in separate attacks targeting a construction site and a military installation, security officials said Saturday. Gunmen killed at least 25 construction workers during an ambush on Thursday in the town of Sabon Gari in Borno State, a senior officer of the Borno State Police Command told The Associated Press. He spoke on condition of anonymity because he was not authorized to speak to reporters.