MIDDLETOWN TOWNSHIP, NJ — The US Navy says an explosion at a New Jersey base has injured eight employees, one of them seriously.

The Navy says the blast happened inside a boathouse at Weapons Station Earle in Middletown as workers were doing boat maintenance around 9 a.m. Tuesday.

One worker has been hospitalized with serious injuries. Seven other workers sustained minor injuries, mostly smoke inhalation.

The Navy says no ammunition was involved in the explosion.

The cause is under investigation.