The Associated Press reports:

GRAND ISLE, La. — An offshore oil rig has exploded in the Gulf of Mexico, west of the site of the April blast that caused the massive oil spill.

Coast Guard Petty Officer Casey Ranel says the blast was reported by a commercial helicopter company about 9:30 a.m. CDT Thursday. Seven helicopters, two airplanes and four boats are en route to the site, about 80 miles south of Vermilion Bay along the central Louisiana coast.

Ranel says it hasn’t been determined whether the structure is a production platform or a drilling rig or whether workers were aboard. Ranel says smoke was reported but it is unclear whether the rig is still burning.

CNN has more. It looks like everyone in the crew has been accounted for:

[Posted at 11:43 a.m.] U.S. Coast Guard Petty Officer Bill Colclough tells CNN that all 13 workers involved in the rig explosion are accounted for, but one person is injured.

Coast Choppers are on the way to the site 80 miles south of Vermilion Bay.

[Posted at 11:33 a.m.] An oil rig has exploded 80 miles off the coast of Louisiana, with 12 people overboard and one missing, the Coast Guard said Thursday morning.

Rescue attempts are under way for at least 12 people, Coast Guard spokesman John Edwards told CNN. 13 people were on board the rig total, Edwards said, noting 12 have been accounted for, but one person was missing.

The accident took place 80 miles off the coast of Louisiana on the Vermilion Oil rig 380, which is owned by Houston-based Mariner Energy.

The Coast Guard has multiple helicopters, an airplane and several Coast Guard cutters en route. It’s unknown if there are any injuries.