Three large U.S. cities have filed a federal lawsuit against the Defense Department, saying many service members who are disqualified from gun ownership weren't reported to the national background check system.

NEW YORK — Three large U.S. cities have filed a federal lawsuit against the Defense Department, saying many service members who are disqualified from gun ownership weren't reported to the national background check system.

New York City, San Francisco and Philadelphia filed the lawsuit Tuesday in Virginia. The cities argue the Defense Department failed to report "significant numbers" of disqualifying records to the FBI's national background check system for gun licensing and sales. That failure allowed a disgraced former Air Force member to buy a high-powered rifle and shoot 26 people to death Nov. 5 in a Texas church.

Local law enforcement officials rely on the FBI's database to conduct background checks on gun permit applications and to monitor purchases. The lawsuit says it must be up to date.

Federal officials didn't immediately comment on the lawsuit.