On Sunday evening, Ukraine's emergency alert application triggered a nationwide notification warning of an air raid. The system also issued additional alerts claiming a radiological threat, a chemical attack, and active street fighting in Kyiv. Authorities later confirmed that all these warnings were false.
A few hours after the incident in Ukraine, Russia reported that its equivalent alert app had similarly broadcast false notifications. Both nations have stated that their respective systems were the target of cyber-attacks.
At this time, it remains unclear who is responsible for these cyber-attacks or whether the two incidents are connected. BBC cyber correspondent Joe Tidy has outlined the current facts regarding the situation as investigations continue.
Sources: BBC News World.