German and British Eurofighters intercepted two Russian Sukhoi Su-27 Flankers on April 25, 2023, including one seen here, and an Ilyushin Il-20 that were flying without their transponders on in international airspace over the Baltic Sea, the German military said. (Twitter/German air force)

Three Russian military planes were intercepted by allied aircraft over the Baltic Sea, Germany’s air force said Wednesday.

Two Sukhoi Su-27 fighter jets and an Ilyushin Il-2 on Tuesday were flying without their transponders on, the German military said.

NATO allies have long taken issue with Moscow over its military’s failure to file flight plans or use transponders. Not following those procedures can pose a safety hazard because they make jets operating in international airspace invisible to civilian radar.

The German air force said Eurofighter jets from both Germany and the United Kingdom were involved in the intercept, which was carried out without incident.

Such encounters are not uncommon over the Baltic and Black seas, where NATO aircraft routinely police the skies for potential intrusions by the Russians.

Still, encounters on occasion can become tense.

In March, a Russian fighter jet collided with a U.S. drone over the Black Sea, causing the unmanned aircraft to crash into international waters.

At the time, U.S. European Command said the incident followed a pattern of dangerous actions by Russian pilots in international airspace.

Stars and Stripes reporter Alexander Riedel contributed to this report.