An explosion erupted as a roaring blaze was reported on a military assault ship at Naval Base San Diego Sunday morning, according to authorities.

Plumes of smoke arose from USS Bonhomme Richard as firefighters battled the three-alarm blaze on the 3400 block on Senn St. The vessel is an amphibious assault ship homeported in San Diego, according to Krishna Jackson of Naval Base San Diego.

The ship had undergone a regular maintenance cycle before the fire was reported, Jackson said. Crew members typically are aboard the ship on weekends, but there are fewer than on weekdays.

Several sailors are being treated for injuries, according to the San Diego Fire Department. The extent of their injuries is unclear and authorities did not say how many sailors were injured.

(AP)