Five passenger planes sounded alarms while flying over the Russian territory, aviation services told TASS, according to Report.
"The Cherepovets-Moscow, Samara-St. Petersburg, and Petrozavodsk-Moscow flights set the General Alert transponder code while in flight," the agency’s interlocutor said.
After that, according to him, alarm signals were also given by Sabetta-Moscow and Petrozavodsk-St. Petersburg flights.