That report is a lie. The rebels say that 200 Polish mercenaries just surrendered at the airport, and I believe them. Obviously they were there with the consent of the Polish government. So really NATO is already fighting in Ukraine.
There have been huge battles at both Donetsk and Lugansk Airports. The airports have been very hard to clean out. They are full of underground passageways and many of the junta forces are underground. The Ukies have been trapped at the Lugansk Airport for a very long time, but they have never been eliminated. Both airports are to the south of their respective cities – Lugansk Airport is quite a bit to the south of Lugansk.