Homeland Security Secretary Michael Chertoff (search) said Wednesday it was a mistake for Hawaii to post a confidential report on its Web site, but the department will continue to communicate openly with state and local authorities about potential terror threats.

Hawaii officials published a draft copy of a confidential Homeland Security report that catalogues ways terrorists might strike in the United States. The report, requested by a presidential directive in December 2003, marks Homeland Security efforts to spur state and local authorities into thinking about preventing attacks.

"My understanding is this was an error," Chertoff said in an interview with reporters. "... It's not going to deter us from working closely with our state and local partners in fashioning these plans."

The report was deleted from Hawaii's site late Tuesday night. Homeland Security spokesman Brian Roehrkasse said several other states, which he declined to identify, had also linked to the report on their Web sites.

But Chertoff said he is going to resist talking publicly about possible terror threats as they unfold until he has definitive information to give.

Chertoff's comments followed a Washington-area anthrax scare this week that appears to have been a false alarm. The two-day scare was marked by conflicting information from local, state and federal officials that led to some broadcast media to inaccurately report anthrax contamination.

"I'm going to mightily resist the temptation to give information out prematurely," Chertoff said.

"What I want to resist is what I sometimes have observed over the years: a temptation to feed the desire for information by putting something out that we are not in a position to speak about definitively," Chertoff said." Our credibility must rest in a sense that when we say something is a fact, we've done everything humanly possible to, in fact, ensure that we are giving the accurate facts out."

However, Chertoff stressed a need to share hunches, suspicions and tips about potential threats with local and state authorities -- creating a careful line for the department to balance.

The department has been working for a year on a National Planning Scenarios (search) plan that outlines a number of plausible attacks -- including by nerve gas, anthrax, pneumonic plague and truck bomb.

Homeland Security "has developed a number of scenarios that will aid federal, state and local homeland security officials in developing plans to become more prepared to prevent and respond to an act of terrorism, should it occur," Roehrkasse said.

The plan also "will help us better target our efforts and resources in improving the nation's preparedness," he said.

Officials said there was no credible indication that such specific attacks were being planned.

The draft plan was first reported Tuesday night on the Internet site of The New York Times.

The report does not hypothesize where such attacks would take place, Roehrkasse said. "The overall goal is to increase the overall baseline preparedness of all states and cities throughout the country," he said.

Besides identifying possible types of attacks, Roehrkasse said the report also estimates how many deaths and amount of economic damage the attacks would cause.

Scenarios also include:

--Blowing up a chlorine tank (search), killing 17,500 people and injuring more than 100,000.

--Spreading pneumonic plague (search) in the bathrooms of an airport, sports arena and train station, killing 2,500 and sickening 8,000 worldwide.

--Infecting cattle with foot and mouth disease (search) in several places, resulting in hundreds of millions of dollars in losses.

But a nuclear bomb, an exploding liquid chlorine tank or a widespread and prolonged aerosol anthrax spray (search) ranked among the most devastating attacks outlined in the report.