The U.S. government Friday launched an investigation into Mariner Energy's Gulf of Mexico platform fire as the Coast Guard said there were no signs of crude oil leaking from the offshore facility.

"We will use all available resources to ensure that we find out what happened, how it happened, and what enforcement action should be taken if any laws or regulations were violated," Michael Bromwich, director of the Bureau of Ocean Energy Management, said in a statement.

On Thursday, Mariner's platform burst into flames, but the crew of 13 was able to escape without harm. The accident follows BP's disastrous Macondo well rupture on April 20, which caused the death of 11 workers and unleashed the world's worst offshore oil spill.

The U.S. Coast Guard had a vessel monitoring the platform through the night and said early Friday there were no signs of pollution in the Gulf.

Helicopters were on the way to the platform, located about 100 miles south of Vermilion, Louisiana, in the Gulf to survey the water for signs of oil.

The fire's cause remains under investigation as company officials had yet to inspect the rig, said Patrick Cassidy, director of investor relations for Houston-based Mariner.

"The sun just came up, and they're flying out there. We're hoping to board the facility today. We'll take an assessment then," he said.

Automated shutoff equipment turned off the flow of oil and gas from the platform's seven producing wells, according to the company.

The fire was the fifth reported at offshore sites operated by Mariner since October 2006, according to government data.

None of the earlier fires caused fatalities, although workers were injured in two of the accidents. The company also suffered a blowout while drilling a well about 90 miles off the Louisiana coast in May 2008, but the well was brought under control within a few hours.

The Vermilion platform was last inspected in January and found to have three minor compliance violations, government data showed.

Shares of Mariner rose 2.5 percent to $23.34 in early trading on the New York Stock Exchange.