LOS ANGELES — A law enforcement official at Los Angeles International Airport says a live stick of dynamite was accidentally left on an old plane at an airport museum for four days.

The official, who was briefed on the incident and spoke on the condition of anonymity because the person wasn’t authorized to speak publicly, said workers on the tarmac found the dynamite Tuesday when they noticed the bright colors on the stick.

It was left behind after a Saturday evening training exercise for K9 officers and their dogs who work at the airport. Though live, the dynamite would have required a detonator or explosive to be set off.

Sgt. Belinda Joseph, a spokeswoman, said the object was a training aid and “there was a certain amount of TNT contained in it” but denied that it was a stick of dynamite.

She said airport police are investigating and have notified the Transportation Security Administration.

The stick was checked out from a TSA explosive storage container for training. Such trainings are done nearly daily, the official said.

TSA officials didn’t immediately respond to a request for comment.

The stick of dynamite was left in a compartment underneath the “Spirit of Seventy Six” plane, the official said. The plane is featured at the Flight Path Learning Center and Museum on the airport’s southern edge.

The plane is outside the museum, which is run by volunteers and hosts school groups and other visitors.

Museum representatives did not immediately respond to a request for comment.