NEW YORK — The main terminal at New York's LaGuardia Airport was evacuated this morning, stranding hundreds of passengers, after a man entered the building with a fake bomb in a bag, police said.

The terminal was evacuated at around 5:30 a.m. today after the man approached security in the airport's C concourse, Port Authority of New York and New Jersey spokesman John Kelly said.

It wasn't clear if the man made a threat, but security officials said he "was just acting crazy," Kelly said. The man's name was not released.

The device in the man's bag was a few batteries and wires, but was not dangerous, police said.

Police later reopened the main terminal, and passengers began re-entering shortly before 9 a.m.

It was not immediately clear how many flights were delayed or canceled by the evacuation.