KYIV, Feb 21 - Ukraine said on Monday about 10 airlines had stopped flying there amid U.S. warnings of an attack by Russian forces massed on its border but insisted its air corridors were still open and flying to the East European country was safe, Reuters reported.

Germany's Lufthansa said it was halting flights to Ukraine from Monday, joining KLM which has already done so.

Scandinavian airline SAS also suspended weekly flights while Air France has decided to cancel Tuesday flights between Paris and Kyiv as a "precautionary measure".