Mysterious drone sightings across Denmark since September 22 have prompted the closure of several airports, with Denmark hinting at possible Russian involvement, charges Moscow has rejected.

Copenhagen is to host an EU summit on Wednesday and Thursday.

"Denmark will host EU leaders in the coming week, where we will have extra focus on security. Therefore, from Monday to Friday, we will close the Danish airspace to all civilian drone flights," Transport Minister Thomas Danielsen said in a statement.

"In this way, we remove the risk that enemy drones can be confused with legal drones and vice versa," he added.

A violation of the ban can result in a fine or imprisonment for up to two years, the ministry said.

Justice Minister Peter Hummelgaard said in the same statement the purpose of the ban was to simplify the work of police and other authorities.

"The police are on heightened alert, and our authorities must use their forces where necessary to take care of Danes and our guests."

He said the ban would mean police would not have to "spend their efforts on civilian drones" that do not pose a problem to security and police.

Danish police said Saturday they had received more than 500 reports of drone flights from the Danish public, most of which were dismissed as being not of interest.