Russian officials said the strategic bombers, two Tu-160 Blackjacks, were in the air for six hours, RIA Novosti reported.

"The aircraft took off from the Libertador airbase in Venezuela on Monday and flew along the South American coast toward Brazil," Lt. Col. Vladimir Drik said.

"The flight was performed in strict accordance with international rules on the use of airspace over neutral waters, without violating the borders of other states."

Though capable of carrying nuclear warheads, the planes reportedly are unarmed, carrying dummy missiles, El Universal reported.

The Russian planes are in Venezuela at the invitation of Venezuelan President Hugo Chavez, an ardent critic of the United States.

Last month, U.S. Secretary of State Condoleezza Rice said Russia was playing a "dangerous game" by conducting flights in regions close to U.S. .borders that Washington considers its defensive air space.

The Russian crews were to meet with Chavez before leaving the country Thursday for the 15-hour return trip to Russia.