US civil liberties groups filed lawsuits in federal courts in New York and Detroit Tuesday, seeking to challenge the legality of President George W. Bush's domestic eavesdropping program and demanding its immediate ending.

The lawsuits, filed in federal court in New York by the Center for Constitutional Rights (CCR) and in Detroit by the American Civil Liberties Union (ACLU) and other advocacy groups, sought a court verdict that would prohibit the administration from conducting surveillance of communications in the United States without judicial warrants.

The New York suit named Bush and the heads of national security agencies including Keith Alexander, director of the National Security Agency (NSA), accusing Bush of exceeding his constitutional powers and challenging the NSA's domestic spying without judicial approval or statutory authorization.

Bush acknowledged last month that he had authorized the NSA to monitor the international telephone calls and e-mails of US citizens without court warrants in an effort to track terrorist suspects.

The revelation of the program has set off a debate about presidential powers, with both Democrats and Republicans questioning whether the administration had exceeded its constitutional limits.

Bush has sought to justify the program as the legal act of a commander-in-chief in a time of war, saying a congressional resolution passed after the 9/11 attacks authorizing him to use force in the fight against terrorism had allowed him to order the program.

But the CCR suit noted that federal law allows the president to conduct warrantless surveillance during the first 15 days of a war and allows court authorization of surveillance for foreign agents or suspected terrorists.

The lawsuit said Bush "unilaterally and secretly authorized electronic surveillance without judicial approval or congressional authorization."

The ACLU lawsuit in Detroit, which also targeted the NAS and its director, included other plaintiffs such as Greenpeace, the Council on American-Islamic Relations and several individuals.

The ACLU said the spying program violates Americans' rights to free speech and privacy under the First and Fourth Amendments of the Constitution.

The lawsuit was filed on behalf of a group of prominent journalists, scholars, attorneys, and national nonprofit organizations who frequently communicate by phone and e-mail with people in the Middle East.

Because of the nature of their calls and e-mails, they believe their communications are being intercepted by the NSA under the spying program which has disrupted "their ability to talk with sources, locate witnesses, conduct scholarship, and engage in advocacy."

The New York Times reported last month that Bush signed an order in 2002 allowing the NSA to monitor the telephone and e-mail communications of "hundreds, perhaps thousands, of people inside the United States" with persons abroad, without a court order as the law requires.

(Xinhua News Agency January 18, 2006)