WASHINGTON, Nov 3: Calling the recent anthrax cases “a second wave of terrorist attacks” on the United States, US President George W. Bush on Saturday praised Americans for their calm and vowed to share credible information.

With his administration under fire for sending mixed messages and being slow to protect postal workers after anthrax-laced letters were discovered, Bush devoted his weekly radio address to laying out the facts so far.

“As we learn more about these anthrax attacks, the government will share the confirmed and credible information we have with you,” Bush said. “I’m proud of our citizens’ calm and reasoned response to this ongoing terrorist attack.”

Anthrax-tainted letters were mailed to Senate Majority Leader Tom Daschle, NBC News in New York and the New York Post newspaper, and four people have died — two Washington postal workers, a photo editor in Florida and a hospital storeroom clerk in New York.

Bush said there was no precedent for the biological attack and praised health officials for acting quickly to distribute antibiotics to those who may have been exposed and swiftly testing post offices and other sites for anthrax spores.

“We are working to protect people based on the best information available,” he said.

But criticism has mounted over the administration’s handling of the anthrax scare after the deadly bacteria was discovered in the letter to Daschle, a South Dakota Democrat.

While congressional aides and some lawmakers were tested and treated for possible anthrax exposure almost immediately, authorities waited almost a week to start testing postal workers at the Brentwood facility, which processes mail for the US Capitol and other Washington areas.

Originally experts said they believed anthrax spores could not escape from sealed envelopes, but Bush said on Saturday, “Now we know differently ... anthrax apparently can be transferred from one letter to another or from a letter to mail sorting equipment.”

ODDS OF TAINTED MAIL “VERY LOW”: While White House spokesman Ari Fleischer sought to assure Americans that their mail was safe, Postmaster General John Potter told the public “there are no guarantees” and urged American to wash their hands after handling it.

Bush said among the more than 30 billion pieces of mail that had moved through the postal service since the Sept 11 suicide plane attacks in Washington and New York, the odds of any one piece being tainted were “very low.”

“As all Americans know, recent weeks have brought a second wave of terrorist attacks on our country; deadly anthrax spores sent through the US mail,” Bush said, advising people to take “appropriate precautions.”

Law enforcement officials did not yet know who sent the anthrax, “whether it was the same terrorists who committed the attacks on Sept. 11 or whether it was other international or domestic terrorists,” Bush said. “We will solve these crimes and we will punish those responsible.”

FBI Director Robert Mueller said on Friday investigators were moving very aggressively to find out who was behind the 17 confirmed cases of anthrax in the past month.

“We are pursuing more than 1,000 leads, including more than 100 that have taken us overseas. We have conducted more than 2,000 interviews to date in that investigation,” he said.

The thrust of the investigation was focused on Trenton, New Jersey, where three anthrax-tainted letters were mailed.

“Despite speculation about the possible source of the anthrax and the motive for the attacks, nothing yet has been ruled out and we continue to follow the evidence wherever it may lead,” Mueller said.

Bush asked Americans who “see anything suspicious” to contact law enforcement authorities. The postal service and the FBI have offered a one million dollars reward for information leading to the arrest and conviction of those responsible.

The president also reminded would-be pranksters that sending false alarms through the mail was a criminal offense. He said at least 20 people had been arrested for anthrax hoaxes and promised “to pursue anyone who tries to frighten their fellow Americans in this cruel way.”—Reuters