Sources say the barges, which contained liquid gasoline, were in the process of being cleaned when the incident began in a ship channel near the George C. Wallace Tunnel. The injured are employees of Oil Recovery Co.
U.S. Coast Guard personnel and Mobile firefighters were called to the scene but were forced to let the blaze burn out due to the intensity of the fire. Authorities evacuated the shipyard.
Witnesses reported at least seven explosions and said some could be heard for twenty miles away.
The cause of the incident is unknown.
The barges are directly across the river from the Carnival Triumph, the ill-fated cruise ship that became disabled in the Gulf of Mexico in February and had to be towed to Mobile.
The barges are owned by Houston-based Kirby Inland Marine, company spokesman Greg Beuerman said.