Fire from a terrorism attack against a tanker ship carrying liquefied natural gas could ignite so fiercely it would burn people one mile away, according to a congressional study.

It examined terror risks on the nation's waterways and concluded that further research is needed to understand the consequences of such a remarkable inferno.

The study by the Government Accountability Office was expected to be released Wednesday. It urged the Energy Department to perform new research on the risks from a major fire or gas release in terror attacks or natural disasters on such tanker ships.

Lawmakers said the latest GAO study coincides with projected increases of 400 percent in liquified natural gas imports over the next 10 years, as energy companies await federal approval on 32 applications to build new terminals in 10 states and five offshore areas. New tanker ships being launched are nearly twice as large as many current tankers, lawmakers said.

"Although LNG tankers have not been subject to a catastrophic accident or attack, we need to ensure regulators are making decisions with a large enough margin of safety to account for the threats in a post-9/11 environment," said Rep. John D. Dingell, D-Mich., chairman of the House Committee on Energy and Commerce. His committee plans oversight hearings on the subject.

Rep. Joe Barton, R-Texas, said such natural gas shipments have an excellent safety record. He noted tankers have operated nearly 50 years without a major spill, and said mandatory "protection zones" around such tankers are believed to be adequate. Still, he described further research on the risks as "only prudent."

The GAO report examined six unclassified studies about the effects of a major spill and fire aboard a double-hulled tanker carrying liquified natural gas. Congressional investigators said most experts believe fierce heat from the intense fire — not explosions — are likely the biggest threat to citizens.

Most experts interviewed by investigators agreed such a fire could burn people's skin roughly one mile away, depending on variables that include the amount of gas released, size of the tanker breach and winds, the GAO report said.

The safety issue is important because there has been a rush of proposed applications for new LNG terminals, sometimes at locations where tanker will travel close to populated areas. The Federal Energy Regulatory Commission has approved 13 applications. A half-dozen facilities have been proposed in the Northeast, often in urban areas.

The need for more LNG terminals reflects a widespread view that there is not enough domestic natural gas to meet future demand, so the demand for LNG imports will grow. LNG is natural gas that has been supercooled to minus 260 degrees Fahrenheit, reducing its volume so it can be transported in a tanker.