Who is jamming aircrafts’ family doctor in the Baltic?

.ON APRIL 29TH Finnair, Finland’s national airline, stated that it would suspend tours to the asian Estonian metropolitan area of Tartu for a month. Recently 2 airplanes were actually compelled to reverse after their GPS signs were actually disrupted. GPS jamming has actually improved dramatically in the Baltic area over recent 2 years.

Who lags it and how harmful could it be?