"On 26 February, the border department of the Russian FSB in the Rostov region recorded firing from Ukraine and falling on the territory of the Russian Federation in the area of the settlement of Nizhnekamyshinsky, Millerovsky district, Rostov region, of three 120 mm mines," the FSB said in a statement.
The FSB added that there were no victims or damage. Verification is currently being undertaken.
On Thursday, Russia began a special operation to demilitarise and "denazify" Ukraine, responding to calls from the Donetsk and Lugansk people's republics for help in countering the aggression of Ukrainian forces. The Russian Defence Ministry said the special operation is targeting Ukrainian military infrastructure only and the civilian population is not in danger. Moscow says it has no plans to occupy Ukraine.