U.S. President George W. Bush on Tuesday signed a bill that authorizes the Central Intelligence Agency (CIA) to continue its practice of questioning terrorism suspects and the prosecution of "captured terrorists" for war crimes.

"This bill will allow the Central Intelligence Agency to continue its program for questioning key terrorist leaders and operatives," Bush said at the White House before signing into law the Military Commissions Act of 2006.

Terming the bill as "one of the most important pieces of legislation in the war on terror," Bush said it allows the United States to "prosecute captured terrorists for war crimes through a full and fair trial."

The bill provides legal protection ensuring that American military and intelligence personnel would not have to fear lawsuits filed by terrorists, simply for doing their jobs, he said.

The president acknowledged several weeks ago that the CIA had been secretly interrogating some suspected terrorists overseas and asked for Congress's authority to try them in military commissions.

The spy agency's secret detention facilities overseas, when revealed last year, caused a political uproar in Washington and attracted criticism worldwide.

"This program has been one of the most successful intelligence efforts in American history. It has helped prevent attacks on our country," Bush insisted.

The CIA program, according to Bush, was "one of the most vital tools in our war against the terrorists" and "helped us gain vital intelligence from Khalid Sheikh Mohammed and Ramzi bin al-Shibh, two of the men believed to have helped plan and facilitate the 9/11 attacks."

While the legislation set the rules for court proceedings for suspected terrorists, it applied to only those selected by the military for prosecution. Most of those held by the U.S. military, believed to be about 14,000 and the majority in Iraq, would not be affected by the law.

Of the hundreds of detainees being jailed at the U.S. military prison at Guantanamo Bay, Cuba, only 10 have been selected for trial. The indefinite detention of others has been condemned by human rights groups as violating international law.

Some or all the 14 suspects held by the CIA in secret prisons and recently transferred to military custody at Guantanamo might also be tried.

Bush authorized the creation of special military tribunals for the terrorism suspects months after the Sept. 11 attacks, but the legality of the system was challenged in U.S. court.

The Supreme Court ruled that the military commissions, or special military tribunals, needed to be explicitly authorized by the Congress, Bush said. "And so I asked Congress for that authority, and they have provided it."

Three weeks before the mid-term congressional elections, the signing of the bill was believed to be a deliberate move aimed to shift public attention, at least momentarily, from the scandals that could cost Republicans their control of Congress.

Editor: Yan