An amputee missing both legs was arrested Thursday after police said he was wheeled into a busy New York City train station and planted a bomb.

Police found the bomb before it could detonate, but the discovery interrupted regional train lines briefly and closed the station for several hours.

The alleged device-a bag of small explosives wrapped in shotgun shells, along with bullets, glue, lug nuts, pens and a ruler-was left in a waiting area at a station in Harlem. Police later surveyed security videos to identify suspects including, Roosevelt Terry, the amputee. Police from the Metropolitan Transportation Authority, which runs the Metro-North Railroad that was shut down, arrested Mr. Terry late in the afternoon.

"If the thing blew, people would have gotten hurt  could have even gotten killed with all the stuff in there," said Bill Morange, director of security for the New York Metropolitan Transportation Authority. The incident is still under investigation.