World Bulletin/News Desk
However, any restrictions on movements between the neighbouring states - which share close cross-border family and business ties - risk aggravating a crisis which erupted when pro-Moscow Ukrainian President Viktor Yanukovich was ousted in February and Russian troops seized control in Crimea.
"This applies to Russian citizens because there is information about possible provocations at the border, up to and including terrorist attacks. Attention will be primarily paid to men of an active age, traveling alone or in a group."
"Russia insists on an immediate official clarification from Ukraine on steps taken by the Ukrainian state border control service. Upon receiving the relevant information from Kiev, we will consider appropriate retaliatory measures," the Foreign Ministry said in a statement.
Russia's flag carrier Aeroflot earlier issued a statement warning passengers that the Ukrainian authorities were "massively restricting" entry to the country.
It indicated that men between the ages of 16 and 60 would be denied entry unless they had proof of a reason to visit, such as family ties or an invitation from a business or individual, or were travelling with their families.Last Mod: 17 Nisan 2014, 23:38