Nemtsov, former first vice-prime minister of Russia, was arrested for his resistance to police during a demonstration staged in Moscow on the eve of the New Year.

The State Duma stated that Nemtsov was arrested because he attempted to break through a police cordon, an act that conflicts with the regulations of demonstration and creates danger to people's safety.

The United States, however, has accused Russia of the arrest, terming it an unreasonable, deplorable and regrettable thing.

A State Duma committee condemned the United States for favoring such publicly recognized illegal act as disobedience to police.

In a press conference, the vice-chairman in charge of Russia-U.S. relations of the State Duma International Affairs Committee voiced misgivings and disappointment over remarks of U.S. State Department officials.

Russia respects the sovereignty of the United States and does not want to interfere in the U.S. judicial system and court business, he said. Russia wants the United States to do so as regards Russia's legitimate rights.

Meanwhile, State Duma members and social activists of Russia reportedly advised U.S. senators to refrain from poking their nose into others' affairs. They described the senators' remarks supporting Nemtsov as interference in Russia's internal affairs.