Smoke pours from the USS Bonhomme Richard at the US Naval base in San Diego on July 12, 2020.

Fire and an ensuing explosion have been reported on a ship at the US Naval base in San Diego.

It was not immediately clear what caused Sunday�s blaze on the Bonhomme Richard, an amphibious assault ship and light aircraft carrier.

According to Krishna Jackson, a Navy spokeswoman, the ship had been docked for scheduled maintenance between deployments.

She suggested that it was unlikely for a docked ship to normally have large artillery onboard.

DEVELOPING: Eleven sailors transported to hospital with minor injuries after explosion on San Diego naval ship.

Fire broke out aboard the USS Bonhomme Richard around 9 a.m. local time, officials said. https://t.co/4PJxuHWjkF pic.twitter.com/52X00QvLqz

— ABC News (@ABC) July 12, 2020

There were, meanwhile, indications that the ship could continue burning for days.

When the fire was reported around 8:30 am local time, some 160 sailors were said to be aboard the ship, which normally carries a crew of roughly 1,000.

Just a lot of shock, just a lot of confusion. You don�t know what happened, if there was you know an attack, or there was a mistake on the ship, you don�t know, said US Navy veteran Joseph Walton.

At least 18 sailors and four civilians were taken to hospital over sustaining what was reported as minor injuries such as smoke inhalation and small burns.

18 Sailors have been transferred to a local hospital with non-life threatening injuries, Naval Surface Forces wrote on Twitter on Sunday afternoon, adding, The entire crew is off the ship and all are accounted.

The three-alarm fire made thick black smoke come out of several points along the 257-meter assault ship.

SOURCE: PRESS TV