Who is congesting aircrafts’ family doctor in the Baltic?

.ON APRIL 29TH Finnair, Finland’s national airline, stated that it will suspend flights to the eastern Estonian city of Tartu for a month. Recently pair of airplanes were obliged to reverse after their GPS signals were interfered with. Family doctor jamming has enhanced sharply in the Baltic location over recent 2 years.

That is behind it as well as how unsafe could it be actually?