The Bureau of Safety and Environmental Enforcement confirmed Wednesday there was an explosion at 10:50 p.m., local time, at a rig approximately 55 miles off the coast of Louisiana.
"No one was on board at the time of the ignition and no one was injured," the BSEE said in a statement.
By Wednesday afternoon, the BSEE said the fire on the rig continued to burn and part of the rig has collapsed.
"There is no observed sheen on the water surface," the regulator said.
The BSEE and U.S. Coast Guard set up a command center to respond to the incident. Two firefighting vessels were trying to control the blaze and a third was on its way.
Walter Oil and Gas Corp. said it lost control of a natural gas well Tuesday morning while preparing the well for production. The BSEE said 44 people were evacuated from the rig before the explosion.
The drilling rig is owned by energy company Hercules Offshore. Both companies said they mobilized in response to the incident.
BSEE Gulf of Mexico Regional Director Lars Herbst said his agency was committed to a safe resolution of the incident.
"Offshore oil and gas operators need to reaffirm their aggressive approach to the safety of well operations in light of this event and other recent well control events," he said in a statement.