Updated

U.S. intelligence agencies have not detected any signs that terrorists are planning attacks because of Hurricane Katrina (search) despite weaknesses the storm exposed in disaster readiness, FBI Director Robert Mueller (search) said Wednesday.

"We have not seen any indication that terrorists see this as a unique opportunity or that this would in any way trigger an attack that perhaps was not in the staging process before," Mueller told reporters at a briefing at FBI headquarters.

While many federal resources have been diverted to the Gulf Coast (search), Mueller said the FBI hffices to keep their eyes on their primary terror-fighting mission and be aware that would-be attackers might consider the country vulnerable.

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The storm heavily damaged two of the four floors of the building that houses the FBI's office in New Orleans, but no evidence in current investigations was lost, Mueller said.

The FBI also is alert to potential fraud related to the rebuilding effort. The bill to the government for Katrina so far is $62 billion and some estimates of the final cost top $200 billion.

"We want to make sure it's spent on rebuilding and not otherwise," Mueller said.

The FBI has received 180 calls to a telephone tip line, 1-800-225-5324, in less than a week, he said.

The bureau also has opened 31 criminal investigations of Web sites that are soliciting hurricane relief donations, with some indictments expected soon, Mueller said. Agents have looked at 3,100 of the 4,600 Web sites that have sprung up since the storm, he said.