The transported individuals were in critical condition, according to ABC News. A Coast Guard spokesman said the two people reported missing were probably overboard.
The explosion and resulting fire sent plumes of black smoke into the sky over Louisiana. There has been no report that any oil spilled into the Gulf. The Louisiana governor's office told ABC News that the rig was non-producing, and the explosion occurred during some kind of maintenance work aboard the platform.
The rig, owned by Black Elk Energy, is about 25 miles southeast of Grand Isle, La. The fire has been extinguished, the Coast Guard said.
The platform is a production platform, unlike the Deepwater Horizon rig, which was drilling an exploratory well for BP in mile-deep water. A small amount of oil spilled from the rig when workers using a torch cut into a 75-foot-long, 3-inch-wide line on the platform
Coast Guard Chief Petty Officer Bobby Nash said late Friday that monitoring continues to show no oil is coming from the well.
Black Elk Energy is an independent oil and gas company headquartered in Houston, Texas.
The explosion and fire comes one day after oil giant BP agreed to a $4 billion settlement for the 2010 Deepwater Horizon explosion in the Gulf, triggering the worst offshore oil spill in the country's history.
ABC News contributed to this report.