'No Chechen troops sent to Ukraine'
Chechnya's Moscow-backed leader has said he has not sent any troops to fight alongside pro-Russia insurgents in eastern Ukraine, but added that some Chechens may have gone there on their own.
The issue is significant because fighting in eastern Ukraine between government troops and pro-Russia rebels has intensified this week with scores killed around Donetsk.
Ukrainian border guards have also reported at least one gunfight as they blocked groups of armed men trying to cross into Ukraine from Russia.
In a statement posted on his Instagram, Ramzan Kadyrov said two-thirds of the three million Chechens live outside the province in Russia's North Caucasus mountains, so he "can't and mustn't know where each of them goes".
"If someone saw a Chechen in the zone of conflict, he's there on his own," he said.
Fighters who looked like Caucasus residents were seen among pro-Russia rebels in eastern Ukraine, where they have seized government buildings and fought Ukrainian forces. Ukraine and the West have accused Moscow of stirring up the unrest, but it has denied the claim.