This was announced by Defense Minister Stepan Poltorak answering a question by Ukrainski Novyny, Censor.NET reports.
"We are investigating into what that was. Maybe it was an accident, for there are people on the other side who are not controlled by the authorities of the so-called "DPR" and "LPR". So at the moment, our representative together with a Russian general and other representatives are checking on the information and determinating causes. After that, a decision will be made of what do to with it," he said.
Poltorak has not specified what Ukraine's further activities will be if it turns out that the shelling was deliberate.