Dozens of people have been killed in Donetsk and Luhansk regions of eastern Ukraine as fighting escalates for Donetsk airport.
According to BBC, a hospital in Donetsk city was hit and artillery fire was reported in many areas of the city.
Ukrainian forces and pro-Russian separatists both continue to claim control over Donetsk airport.
Ukrainian authorities claim that the Russian troops have crossed the border as Russia warned Ukraine not to make any strategic mistake.
Russia said that their regular forces are not present in eastern Ukraine but accepted that there were some "volunteers" fighting alongside rebels.