More than 30 people have been arrested in Moscow and St. Petersburg as ultra-nationalists staged rallies over the death of Ivan Agafonov. Agafonov, 19, died after a scuffle outside a Moscow nightclub on Aug. 13 and Dagestan-born martial arts champion Rasul Mirzayev is accused of throwing the fatal punch. That has angered right-wing groups, who are planning a wave of protests against “Caucasian lawlessness”. And...