Ten convicted Russian spies were flown out of Vienna on Friday on a Russian plane after arriving on a charter flight from New York, a Russian special service source said.
An aviation source said the plane is expected to arrive at Domodedovo International airport in Moscow at 17:30 p.m. local time (13:30 GMT).
The ten pleaded guilty on Thursday to charges of failing to register as agents of a foreign government and were deported from the United States in exchange for the release by Russia of four Russians convicted of spying for the West and pardoned by Russian President Dmitry Medvedev.
The Russian spies in the United States agreed never to return without permission from the attorney general.
The ten convicted Russian spies in the United States are Anna Chapman, Mikhail Kutzik and Natalia Pereverzeva, both of whom had been living under the names Michael Zottoli and Patricia Mills, Mikhail Semenko, Juan Lazaro and Vicky Pelaez, Richard and Cynthia Murphy, whose real names are Vladimir Guryev and Lidiya Guryeva, Tracey Lee Ann Foley and Donald Howard Heathfield, whose real names are Andrei Bezrukov and Elena Vavilova.
The Kremlin said on Friday that Medvedev signed a decree to pardon four individuals imprisoned in Russia for allegedly working for Western intelligence agencies.
The pardoned individuals are Alexander Zaporozhsky, Gennady Vasilenko, Sergei Skripal and Igor Sutyagin.
All four appealed to the Russian president to free them after admitting their crimes against the Russian state, press secretary Natalia Timakova said.
U.S. officials also said that the arrest of alleged Russian spies shortly after Medvedev's visit to the United States was a coincidence and was forced by the fact that one of the suspects had immediate plans to leave the country.
MOSCOW, July 9 (RIA Novosti)
