According to Interfax news agency, one of the Ukrainian prisoners can be Air Force pilot Nadezhda Savchenko.

“The presidential plane, carrying Russian servicemen Evgeny Erofeev and Alexander Alexandrov, will soon touch down at Rostov-on-Don’s airport, where Ukrainian Air Force pilot Savchenko has already been brought,” Interfax cites its own source as saying.

Nadezhda Savchenko will be exchanged under an extradition treaty between the two countries, Interfax quotes its second source as saying.

“Representatives of the Russian law enforcement agencies escorting Savchenko have already arrived in Rostov-on-Don. Under a deal reached with the Ukrainian authorities, they will be handed two Russian servicemen detained in Ukraine,” an unnamed official said.

It was reported earlier that Ukrainian President Pyotr Poroshenko received a letter seeking a pardon for two convicted Russian servicemen Yevgeniy Yerofeyev and Alexander Alexandrov.