WATCH: Explosion Aboard Naval Ship Cause Large Fire

WATCH LIVE: Naval Ship USS Bonhomme Richard Catches Fire In California

A three-alarm fire broke out Sunday morning aboard the USS Bonhome Richard at Naval Base San Diego, military officials said. At least one person was treated for smoke inhalation.

No other injuries have been reported so far after the blaze broke out shortly before 9 a.m. local time. The cause of the fire is under investigation. Video posted on social media showed crews responding and smoke in the air. The San Diego Fire Department, who assisted in the emergency, said there was an explosion.

The USS Bonhomme Richard is an 840-foot amphibious assault vessel and the Navy said there were about 200 sailors and officers on board at the time of the incident. It was unclear where onboard the fire started.

The Associated Press said the vessel was undergoing routine maintenance at the time of the fire. San Diego is the home port for Bonhomme Richard.