According to the BBC, some U.S. senators are not pleased with the Bush administration to allow to National Security Agency to conduct some domestic spying without a warrant.

Some excerpts:

The NSA is normally barred from eavesdropping within the US.

Republican Senator John McCain called for an explanation, while Senator Arlen Specter, Senate Judiciary Committee chairman, called it "inappropriate".

Previously, surveillance on American soil was generally limited to foreign embassies. ...

American law usually requires a secret court, known as a Foreign Intelligence Surveillance Court, to give permission before intelligence officers can conduct surveillance on US soil.

Administration officials refused to confirm or deny details of the New York Times report, but issued a robust defence of anti-terrorist operations, saying they had prevented several attacks - including one on targets in Britain.

When asked about the programme on US TV, the Secretary of State, Condoleezza Rice, said: "The president acted lawfully in every step that he has taken".

"He takes absolutely seriously his constitutional responsibility both to defend Americans and to do it within the law," she said.

Intense concern

To opponents of the Bush administration, the alleged bugging programme is reminiscent of the widespread abuse of power by the security services during the Vietnam War when anti-war activists were monitored illegally, says BBC Washington correspondent Justin Webb.

In a separate development on Friday, the Senate refused to reauthorise provisions of the Patriot Act, extending government surveillance rights.