(The Hill) — The European Aviation Safety Agency (EASA) is warning airlines not to fly over or near Ukraine as Russia attacks its neighbor, Reuters reports.

“In particular, there is a risk of both intentional targeting and misidentification of civil aircraft,” EASA warned in a conflict zone bulletin, according to the news service. 

“The presence and possible use of a wide range of ground and airborne warfare systems poses a high risk for civil flights operating at all altitudes and flight levels,” EASA added.

The news service added that Ukrainian airspace was closed to civilian flights early Thursday morning.

Nearby nations including Moldova and Belarus, where Russian forces were deployed ahead of the attack on Ukraine, also reportedly closed their airspace.

Air traffic maps in Europe early Thursday showed flights over northern and western Europe, with carriers avoiding airspace over Ukraine, Moldova, and Belarus, Reuters reports. 

The United States — as well as Canada, the U.K., France and Italy — had earlier urged airlines to avoid Ukrainian airspace, though they did not ban air traffic over the countries. 

Additionally, Reuters noted that Wizz Air, a British budget carrier airline, joined Lufthansa and KLM airlines in suspending flights in and out of Ukraine.