All four Moscow airports reopened after a brief time, including an additional airport in Kaluga which reopened later this afternoon - as of yet no reason has been given

All four of Moscow's airports including another about 100 miles southwest of the Russian capital were temporarily shut down for undisclosed security concerns, authorities said.

All four of Moscow’s airports were temporarily closed without any reason given, according to Russia’s aviation watchdog. ‘Aircraft crews, air traffic controllers and airport services are taking all necessary measures to ensure flight safety,