Updated 11:13 PM ET
MOBILE, Ala. Firefighters from Mobile, Ala., and U.S. Coast Guard crews responded Wednesday night to four explosions and a fire on fuel barges in the Mobile River.
Officials were responding to two explosions and a fire at natural gas barges when a third explosion occurred, Mobile Fire and Rescue spokesman Steve Huffman said. It was not immediately clear if the third explosion was on one of the barges that were already engulfed in flames.
A fourth explosion was reported just before 10 p.m. CDT.
CBS affiliate WKRG Mobile reported of no fatalities. Three people were hospitalized with burns and information on their conditions was not immediately available.
Fire officials said they planned to let the barges burn into the night because the situation was too unstable.
The explosions happened in an area of the river east of downtown Mobile, Huffman said. U.S. Coast Guard Petty Ofc. Carlos Vega said the blast happened in a ship channel near the George C. Wallace Tunnel which carries traffic from Interstate 10 under the Mobile River.
The explosions rattled the windows of houses in downtown, blew doors open in the Spanish Fort area and aftershocks were reported in Bay Minette and Fort Morgan, according to the Mobile Press-Register. Video from WALA-TV shows flames engulfing a large section of the barge.
Coast Guard officials were on their way to the scene Wednesday night and the cause of the explosion was not immediately clear, Vega said. CBS News has learned from the Mobile, Alabama Coast Guard that a barge was being cleaned when it somehow caught fire.
The explosion comes two months after a Carnival cruise ship was towed to Mobile after becoming disabled during a February cruise by an engine room fire, leaving thousands of passengers to endure cold food, unsanitary conditions and power outages. The ship is still undergoing repairs there and was sheltering in place late Wednesday.
Two shipyard workers fell into Mobile Bay on April 3 during a windstorm that dislodged the disabled Carnival Triumph cruise ship from its mooring. While one worker was rescued, the other's body was pulled from the water more than a week later.