An emergency service source said that Utair flight UT705 en route to Berlin from Moscow, which earlier issued an alarm due to a malfunction of the air conditioning system, safely landed at Vnukovo Airport at around 13:40 local time (10:40 GMT).
The pilots decided to turn around and go back to Russia after experiencing technical problems on board while crossing Lithuanian airspace.
"A Boeing 737 en route from Moscow to Berlin turned around over the city of Kaunas [Lithuania] due to problems with the air conditioning system", a source explained.
According to Utair, the crew acted correctly and very professionally.