he attacks sent service members scrambling for cover as bullets smashed through the windows.

Federal authorities said they were investigating the possibility of a terrorist act but had no evidence yet that anyone but a lone gunman was involved. They also said there was no indication that the general public was in danger. The FBI has taken charge of the case.

Authorities identified the gunman as Muhammad Youssef Abdulazeez, 24, of Hixson, Tennessee. An official said there was no indication that he was known to federal law enforcement.