A Defence spokesman of Ukraine said hundreds of Russian troops are likely to have been killed in the incident.
Ukraine’s border guard agency also said the Russian military attacked the country from neighbouring Belarus.
The agency said the Russian troops unleashed an artillery barrage as part of an attack backed by Belarus.
“Attacks on border units, border detachments and checkpoints are carried out with the use of artillery, heavy equipment and small arms. The work of enemy sabotage and reconnaissance groups is also recorded,” ,” the agency said in a statement.
Russian airstrikes reportedly hit an apartment complex in south of Kharkiv, Ukraine.
The European Union Aviation Safety Agency had warned air operators of a high risk to civilian aircrafts over Ukraine, reminding air operators that this is now an active conflict zone.
In the bulletin issued early Thursday, EASA said, Airspace and critical infrastructure, including airports, are exposed to military activities which result in safety risks for civil aircraft. In particular, there is a risk of both intentional targeting and misidentification of civil aircraft.