Armored vehicles and artillery were part of the columns , Avakov said , citing Ukrainian intelligence . Russian tanks crossed border into Russia , Russian BBC Minister Avakov says . A skirmish resulted , with Ukrainian forces attacking one column , Avakov says . Russia 's foreign minister tells BBC the claims are false . Ukrainian President talked to Ukrainian leader about peace plan , media office says .
Russian tanks crossed border into Russia , Russian BBC Minister Avakov says . A skirmish resulted , with Ukrainian forces attacking one column , Avakov says . Russia 's foreign minister tells BBC the claims are false . Ukrainian President talked to Ukrainian leader about peace plan , media office says .