Updated at 2:35 p.m. Eastern.
Russia angrily denounced the U.S. arrest ofas an unjustified throwback to the Cold War, and senior lawmakers said some in the U.S. government may be trying to undercut President Barack Obama's warming relations with Moscow.
The Russian Foreign Ministry said Tuesday it was regrettable that the arrests came amid Mr. Obama's push for a "reset" in Russian-U.S. ties.
"These actions are unfounded and pursue unseemly goals," the Foreign Ministry said in a statement. "We don't understand the reasons which prompted the U.S. Department of Justice to make a public statement in the spirit of Cold War-era spy stories."
Russia's Foreign Minister Sergey Lavrov noted that U.S. authorities announced the arrest just days after Russian President Dmitry Medvedev visited the United States.
"They haven't explained to us what this is about," Lavrov said at a news conference during a visit to Jerusalem. "I hope they will. The only thing I can say today is that the moment for doing that has been chosen with special elegance."
Medvedev met with Mr. Obama at the White House last week after the Russian leader visited high-tech firms in California's Silicon Valley. The two presidents went out for cheeseburgers, exchanged jokes and walked together in the park.
The arrests of what U.S. officials described as a deeply embedded Russian espionage network active for up to a decade follow a string of other spy scandals that have roiled ties between Moscow and Washington since the end of the Cold War. The FBI bust - the biggest such case in years - would again put their relations to a test.
Some of the 11 suspected undercover agents worked in pairs so they could blend into American society as the couple next door. Aside from fake identities, they allegedly used elaborate spying techniques - some of which include secret messages encrypted inside pictures on publicly-available web sites and others sent in scrambled radio transmissions, reports CBS News correspondent Bob Orr. Money and information was often passed in personal meetings, with the suspects and their handlers speaking in code.
Most of the suspects purported to be citizens of the U.S. or Canada, according to court papers. One was using the identity of a dead person, another's birth certificate was found to be false.
The U.S. court documents included photos of one defendant as a young woman that were taken on Soviet film. Another who purported to be a native Uruguayan with Peruvian citizenship was heard talking about his childhood in Siberia.
The suspects were posing as civilians while trying to infiltrate U.S. policymaking circles and learn about U.S. weapons, diplomatic strategy and politics. The arrests followed a multiyear FBI investigation.
On Tuesday, a Cyprus police spokesman said authorities havewanted by U.S. authorities on suspicion of espionage and money laundering. Spokesman Michalis Katsounotos says 54-year-old Christopher Robert Metsos was arrested early Tuesday at Larnaca airport trying to fly to Budapest, Hungary. He is suspected of being an 11th defendant in the U.S. case, a man accused of delivering money to the agents. He was freed on bail.
In one of the more bizarre episodes described in the court documents, money intended for the Russian agents was buried in a New York field and only retrieved by them two years later.
A secret Russian agent identified as Christopher Metsos was surreptitiously handed the money by a Russian official as the two swapped nearly identical orange bags while passing each other on a staircase at a commuter train station in New York.
After giving some of the money to one of the defendants, Metsos drove north and stopped his car near Wurtsboro, N.Y. Using data from a GPS system that had been secretly installed in his car, agents went to the site and found a partially buried brown beer bottle. They dug down about five inches and discovered a package wrapped in duct tape, which they photographed and then reburied.
Two years later, video surveillance caught two of the defendants digging up the package.
Oleg Gordievsky, a former KGB spy who defected to Britain in 1985, told The Associated Press on Tuesday that Russiaspying inside the United States.
Foreign Ministry spokesman Igor Lyakin-Frolov told the AP the information given by U.S. authorities looked "contradictory." He wouldn't comment further.
The main Russian spy agency, the Foreign Intelligence Service, known by its Russian acronym SVR, refused to comment on the arrests.
Nikolai Kovalyov, the former chief of the main KGB successor agency, the Federal Security Service, said some of the U.S. charges against the alleged spies resembled a "bad spy novel."
"Would you act like that in the 21st century?" he said in a reference to allegations that agents retrieved cash that had been buried in the ground years before.
Kovalyov, now a lawmaker, said the arrests were an attempt by some "hawkish circles" in the United States to demonstrate the need for a tougher line toward Moscow. Kovalyov added that Russian-U.S. ties will continue to improve despite the spy scandal.
"Our two great powers must stand together," he said.
He said Russia would reciprocate only "if the American don't stop at that and risk evicting our diplomats," the ITAR-Tass news agency reported. He added that it would be unlikely.
Other senior Russian lawmakers also alleged that part of the U.S. government resents warmer ties with Russia.
"Not all of them support Obama's policy," Mikhail Grishankov, a deputy head of security affairs committee in the lower house of Russian parliament, the State Duma, told Associated Press Television News. "There are forces interested in tensions."
Grishankov added the arrests were unlikely to thwart a new warmer spell in ties.
Leonid Slutsky, a deputy head of the Duma's foreign affairs committee, predicted that Moscow and Washington would be able to overcome the setback posed by the arrests.
"The scandal shouldn't worsen the ties," he told reporters.
Alexander Torshin, a deputy speaker of the Russian parliament's upper house, also said they are unlikely to derail ties.
"It's not a return to the Cold War, and I'm sure that this incident won't develop into a large-scale spy scandal," Torshin said, according to the state RIA Novosti news agency.