Russian channels on Telegram are explicitly mentioning the threat of a drone attack. On Thursday around 12 PM Eastern Time,

At five airports - four in the Moscow region and one in the adjacent Kaluga region - arrivals and departures were suspended. The Russian aviation market regulator, Rosaviatsiya, states this is due to safety concerns.

"To ensure the safety of civil aircraft flights, temporary restrictions have been introduced on the operation of Sheremetyevo, Domodedovo, Vnukovo, Zhukovsky and Kaluga airports," Rosaviatsiya said on Dec.