Cross-border clashes escalate between Russia and Ukraine

Russia claims to have defeated and killed scores of "Ukrainian nationalists" who crossed into Russia from Ukraine after two days of combat, in what appears to be one of the biggest incursions of its kind of the 15-month-old war. The two groups that claimed responsibility describe themselves as Russian armed dissidents seeking to overthrow President Vladimir Putin. Russia has blamed Ukraine for the attack, which Kyiv has denied. The raid appears to be the biggest into Russia since the war began.