Soon after the Sept. 11 terror attacks in 2001, US President George W. Bush secretly authorized domestic eavesdropping despite legal prohibitions against the practice, The Washington Post reported Friday.

Under this authorization, the National Security Agency (NSA) eavesdropped, without warrants, on as many as 500 people inside the United States at any given time since 2002, according to the report.

Bush's endorsement of the secret program also allows the NSA to monitor international phone calls and international e-mails.

Before the program began, the NSA typically limited its domestic surveillance to foreign embassies and missions and obtained court orders for such investigations, according to the report.

Overseas, 5,000 to 7,000 people suspected of terrorist ties are monitored at one time.

The report said US government officials credited the program with uncovering several terrorist plots, including one by Iyman Faris, an Ohio trucker who pleaded guilty in 2003 to supporting al Qaida by planning to destroy the Brooklyn Bridge.

But some NSA officials were so concerned about the legality of the program they refused to participate.

Questions about the legality of the program had led the Bush administration to temporarily suspend it last year and impose new restrictions, according to the report.

A spokesman of the American Civil Liberties Union (ACLU), a prominent rights group, said the administration has gone so far in violating American civil liberties to the extent where it seems to be a violation of federal law.

The White House has so far made no comment on the issue. A senior official reached by the newspaper by phone said the issue was too sensitive to talk about.

(Xinhua News Agency December 17, 2005)