Russia’s border guard service said Sunday, March 2, that some 675,000 Ukrainian citizens have migrated to Russia since the beginning of 2014 amid fears of uncertain future in crisis-hit Ukraine’, RIA Novosti reported.

The border guards said the majority of refuge-seeking Ukrainians took up temporary residence in neighboring Belgorod, Rostov, Bryansk and Kursk regions as well as in Krasnodar Territory.

In February alone, the migration flow from Ukraine to the Rostov region increased by 53 percent, while exodus to the Kursk region rose by 71 percent, showing signs of a looming “humanitarian catastrophe,” according to the border guard service.

Russia’s Federal Migration Service said earlier it has noted a sharp spike in applications from Ukrainian citizens residing in Russia seeking Russian citizenship.