Ukraine said it was closing borders to Russian citizens as part of martial law measures. Kyiv-Moscow tensions have escalated since Russia stopped Ukrainian ships and detained sailors in the Sea of Azov.
On Saturday, the Ukrainian government denied 100 Russian citizens entry to the country for the duration of a 30-day period of martial law approved last Monday.
President Petro Poroshenko said on Saturday security had been stepped up at vital infrastructure sites such as nuclear power stations and Black Sea ports. In a statement on Twitter, he claimed that Russia "has deployed land forces of around 80,000 Russian troops, about 1,400 artillery and missile systems, 900 tanks, 2,300 armored vehicles, about 500 planes and 300 helicopters."
At the G20 summit being held in Argentina, Chancellor Angela Merkel met briefly with Russian President Vladimir Putin, and the two agreed to hold adviser-level talks involving Germany, France, Russia and Ukraine.
The Ukrainian president announced Friday that his government was restricting entry into Ukraine and barring male Russian nationals between the ages of 16 and 60. Poroshenko said the move was intended to prevent undercover Russian military personnel from entering the country after Russia stopped several Ukrainian ships and detained its sailors.
A spokesman for the Ukrainian border patrol told Ukrainian media on Saturday that some of those denied entry were carrying Russian identity documents instead of proper passports.
Andrei Demchenko, a spokesman for Ukraine's border guards, said that "the vast majority of (them) couldn't confirm the purpose of their trip to Ukraine."
"Some of them didn't have the necessary documents to enter Ukraine and others had exceeded the period of stay in our country," he added.
For its part, Moscow blocked 40 Ukrainians from entering Russia.
NGO director 'denied entry'
Kyiv's entry ban also extends to Russians with residency in other countries.
Sergey Medvedev, a Russian national who is a director at the Berlin-based NGO Dekabristen e.V., which works for civic cooperation with Eastern Europe, wrote on Facebook that he was blocked from going to the Ukrainian capital for a conference.
In an interview with DW, Medvedev said that Ukrainian officials asked about the purpose of his visit and other details, but only 10 minutes later told him he could not enter.
The ban was not restricted to Russian men; Medvedev said he also saw two young Russian women being sent back.
Ukrainian officials justified the action by saying the purpose of Medvedev's visit to the country "was not transparent," although he said that he provided several documents and an invitation stating the purpose of his trip.
International mediation needed
Medvedev claimed that he had been deported on the basis of flimsy reasons, and that no reference to martial law was made. "From a legal point of view, the border officials gave a wrong reason to refuse my entry — saying the purpose of the visit was unestablished."
He said he understands that the measures are intended to protect national security in Ukraine, but blocking Russian citizens from entering the country "will affect civic dialogue and exchange between the civil societies of the two countries."
"Russian and Ukrainian politicians won't talk to each other until there is international mediation. In this situation, we, the civil society representatives, can be important for [improving] bilateral relations. But now we [Russian and Ukrainian civil society actors] find themselves cut off from each other and can only meet in Berlin, Warsaw or in some other neutral place," Medvedev told DW.
rs, shs/jm (dpa, AFP)