Two planes, believed to be carrying 14 spies involved in the largest swap deal between the United States and Russia since the Cold War, left the Vienna airport on Friday.

The flights, one from Russia and the other from the United States, landed at the airport at 11:15 a.m. local time (0915 GMT).

The Russian plane was believed to be carrying 10 Russian agents who been deported from the United States in exchange for four pardoned agents, including nuclear scientist Igor Sutjagin and three double agents.

The Russian Foreign Ministry confirmed the spy swap in a statement issued earlier Friday, saying the deal was based on humanitarian grounds and principled constructive partnership.