Three Russian military planes flying without transponder signals were caught in international airspace over the Baltic Sea on Wednesday, according to Germany’s Luftwaffe.

According to the German air force, Germany and the United Kingdom dispatched Eurofighter planes to identify the two Sukhoi Su-27 fighter aircraft and one Ilyushin Il-20 aircraft.

It published multiple photographs of the Russian plane in mid-flight.

Russian military aircraft regularly fly from mainland Russia to Kaliningrad and back, meaning that such encounters are fairly routine in the region.

Germany handed over responsibility for NATO’s Baltic air policing mission to Britain earlier this month. NATO allies pitch in to protect the air space there because Lithuania, Latvia and Estonia do not have their own fighter jets.