Flight broadcasts from within North Korea are becoming more frequent, tracking data shows, after nearly two years of relative radio silence in the country’s airspace.

According to Automatic Dependent Surveillance-Broadcast (ADS-B) data from FlightRadar24, at least three flights have taken place within the North since Sept. 13. Three flights also appeared on flight tracking systems in August but only momentarily, according to NK Pro’s Aviation Tracker.

North Korean flight broadcasts over ADS-B have become relatively rare over the course of the COVID-19 pandemic, and those that have appeared in open-source trackers have transmitted mostly incomplete data.

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