Ukraine has charges two suspected Russian soldiers who were captured during a gun battle in the separatist eastern region of Lugansk with involvement in "terrorist activity," a security official said Wednesday.

Ukrainian Security Service spokesman Markiyan Lubkivsky wrote on Facebook that Captain Yevgeny Yerofeyev and Sergeant Aleksander Aleksandrov, now convalescing in a Kiev military hospital, were also allowed to telephone their relatives in Russia.

Moscow has said that the two men were once members of the Russian armed forces but had been decommissioned by the time they crossed into the Ukrainian war zone nearly two months ago.