VENICE, La. (AP) — Coast Guard officials said an oil rig exploded off the coast of Louisiana, sending four people to hospitals Friday. Two were believed to be missing.

Petty Officer 3rd Class Jonathan Lally, a spokesman for the Coast Guard, did not immediately have information on the conditions of those taken to hospitals.

The rig, a production platform owned by Black Elk Energy, is about 25 miles southeast of Grand Isle, La.

Lally says two helicopters, an airplane and small boats were sent to the area. He did not know if the fire caused by the explosion had been put out yet.

The platform is a production platform, unlike the Deepwater Horizon rig, which was drilling an exploratory well for oil giant BP in mile-deep water well to the east of Friday’s reported explosion.

A spokesman for Black Elk Energy could not immediately be reached for comment.

Black Elk is an independent oil and gas company headquartered in Houston, Texas.

The company’s website says it holds interests in properties in Texas and Louisiana waters, including 854 wells on 155 platforms.