Fresh fears about drilling in the Gulf of Mexico were raised today when fire forced workers to abandon an oil and gas platform, just six months after the BP explosion that created an environmental disaster in the region.

The company, Mariner Energy, said none of the 13 workers, who fled the platform and took to the sea in immersion suits, were injured. The coastguard said they were taken by ship to a nearby platform and from there to hospital in Houma, Louisiana, to be checked. Ships, helicopters and a plane were sent by the coastguard from Houston, New Orleans and Mobile.

Photographs of smoke billowing from the rig alarmed politicians, environmentalists, fishermen and others on the Gulf coast, still coping with pollution from the BP oil spill.

Peter Troedsson, a spokesman for the coastguard, said the fire had been put out and, in spite of initial reports of an oil slick, ships and helicopters at the scene could see no pollution round the platform.

He said the initial report had come from a Mariner ship at the scene, but the coastguards could see no oil sheen at the site.

The fire is a setback for the oil industry, which has been arguing that drilling in the Gulf is safe and that the BP explosion was a rare event. It came only 24 hours after companies including Mariner had staged a rally in Houston against a moratorium on deepwater drilling in the Gulf. About 5,000 employees had been bussed in for the rally.

Barbara Dianne Hagood, a spokesman for Mariner Energy, told the Financial Times on Wednesday: "I have been in the oil and gas industry for 40 years, and this [the Obama] administration is trying to break us. The moratorium they imposed is going to be a financial disaster for the Gulf coast, Gulf coast employees and Gulf coast residents."

Another spokesman for Mariner, Patrick Cassidy, said he did not anticipate any pollution, as the platform had not been drilling and there had been no blowout. "There is no hydrocarbon spill," he said.

The fire had broken out on a facility above the water, at some distance from the wells, he added.

Dave Reed, an oil worker on a platform about 14 miles away, told CNN he could see the smoke and that a call had gone out for ships, helicopters and planes in the region to divert to the area. "It took an hour for the helicopters to get here and all 13 were taken from the water," Reed said.

The alarm was raised by a commercial helicopter flying over the platform. A coastguard spokesman, chief petty officer John Edwards, said: "We were able to confirm that all people were accounted for."

The fire broke out on the platform Vermilion Oil Rig 380, about 90 miles south of the Louisiana Coast and west of the earlier BP explosion that had killed 11 workers.

Both the White House and the coastguard said they did not anticipate any pollution, but that ships equipped with facilities to help clean up spills had been sent to the area as a precaution.

The White House press secretary, Robert Gibbs, said: "We obviously have response assets ready for deployment should we receive reports of pollution in the water." The White House stressed that, unlike the BP rig, the platform was not a deepwater facility and was only working to a depth of 340ft.

BP's attempts to cap its well, which saw hundreds of millions of gallons of oil spill into the Gulf, were bedevilled by the depth at which they had been drilling. They finally capped the well in July.

Mariner is a small company in the process of being taken over by the Apache oil company in a deal worth an estimated $3.9bn (£2.5bn). The deal has not yet been completed. Shares in both companies fell after news of the fire.