WASHINGTON — The Coast Guard lacks the resources to adequately protect tankers carrying liquefied petroleum or crude oil from a possible terrorist attack, congressional auditors reported Wednesday.

The report by the Government Accountability Office said the Coast Guard is stretched too thin in some cases “to meet its own self-imposed security standards such as escorting ships carrying liquefied natural gas.”

Also, said the report, some ports visited by the government auditors did not have the resources needed to promptly respond to a terrorist attack on a crude oil or LNG tanker, including a shortage of fire boats and inadequately trained people.

The GAO report said past incidents overseas have shown that fuel-carrying tankers are significant terrorist targets, with the biggest concern being a suicide attack. The report noted the 2002 suicide boat attack on a tanker off the coast or Yemen, for example.

While the GAO cited no specific terrorist threat to a vessel or U.S. port, the report said “the threat of seaboard terrorist attacks on maritime energy tankers and infrastructure is likely to persist,” with the greatest risks at shipping chokepoints far from U.S. shores.

But it also said the United States “has limitations” in its ability to head off a terrorist plot overseas and that actions taken in U.S waters and ports “carry increased importance.”

The Coast Guard has the primary responsibility for maritime security. It monitors arriving ships, boards vessels before they reach port and conducts escort patrols of incoming LNG tankers.

But the GAO auditors said Coast Guard documents show that at some ports a lack of resources has hindered some Coast Guard units from meeting their security duties, including vessel escorts and boarding. It said the Coast Guard has sought to prioritize its security activities to focus on the most risky shipments such as LNG, but that may have reduced security involving other commodities such as crude oil.

“We know that terrorists are looking for the weakest link in our security efforts, and this GAO report is a timely reminder that LNG and oil tankers are serious targets,” said Rep. Edward Markey, D-Mass., who long has been concerned about security for LNG tankers going into Boston harbor.

Rep. John Dingell, D-Mich., chairman of the House Energy and Commerce Committee, said he would support more money for the Coast Guard for these security activities.

“If there is an attack on an energy tanker or terminal in a U.S. port there could be significant economic environmental and public safety consequences,” Dingell said.

Tankers carrying liquefied petroleum now account for 3 percent of U.S. natural gas supplies and that is expected to grow significantly in the coming years. LNG imports now are equal to two large tankers arriving at a U.S. port every three days. There are four onshore LNG terminals operating, but federal regulators have approved construction of at least 11 new facilities, and dozens more have been proposed.

Fire from a terrorism attack against a tanker ship carrying LNG could ignite so fiercely it would burn people one mile away, according to various government studies.

A report by the GAO in March concluded that further research is needed to understand the consequences of an LNG inferno. But it also examined six unclassified studies about the effects of a major spill and fire aboard a double-hulled LNG tanker, concluding that fierce heat from the intense fire — not explosions — would be the biggest threat to the public.

LNG is natural gas that has been cooled to minus 260 degrees, so that it becomes a liquid that can be transported in a tanker. Once brought ashore it is warmed so that it again becomes natural gas.

The GAO report was requested by Dingell, Markey and Rep. Joe Barton, R-Texas.

Barton said in a statement that most LNG safety experts surveyed by the GAO said the protection zones required for LNG tankers and terminals will protect the public.

“Who can disagree that in an age of suicide bombers and America-haters, the vessels which deliver energy to Americans warrant protection,” Barton said. “We’ll need to protect the tankers, but we’ll require far fewer of them if we can summon the political will to produce our own energy from our own reserve.”

Barton has been a strong advocate for opening more offshore waters for natural gas exploration and drilling and more domestic oil and gas production.