The United States' new anti-terrorism law contains a number of provisions that fail to meet obligations the U.S. has under international law, with some appearing to contradict the right to a fair trial, a key U.N. rights expert said Friday.

Martin Scheinin, the United Nations' expert on protecting human rights in combatting terrorism, said the Military Commissions Act signed into law earlier this month by U.S. President George W. Bush "contains a number of provisions that are incompatible with the international obligations of the United States under human rights law and humanitarian law."

"One of the most serious aspects of this legislation is the power of the president to declare anyone, including U.S. citizens, without charge as an 'unlawful enemy combatant' — a term unknown in international humanitarian law," said Scheinin, a legal expert from Finland.

As a result, he said, those detainees are subject to the jurisdiction of a military commission composed of military officers — rather than a court of law.

He also deplored the denial of the habeas corpus rights of foreigners — including legal, permanent U.S. residents — to challenge the legality of their detention, "in manifest contradiction with" the International Covenant on Civil and Political Rights, a treaty that the U.S. ratified in 1992.

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