Kiev accused Russia on Friday of sending more tanks and troops into eastern Ukraine and said they were heading toward the rebel-held town of Novoazovsk on the southern coast, expanding their presence on what it fears could be the next battlefront.
Russia did not immediately respond to the accusation, which if confirmed would go further to kill off a European-brokered truce that was met by relentless rebel advances after it came into force last Sunday. Moscow has always denied accusations that its forces are fighting in Ukraine.
Nevertheless, there were signs that the rebels may be prepared to halt their advance, having achieved their main military objective this past week by seizing the strategic town of Debaltseve in defiance of the cease-fire.