How do they know? Did the occupants of the plane leave a note saying why they had stopped? Even if the tanks were found to be empty - that might not have been the reason they stopped. We have no way of knowing their true intentions.
Regards,
Because they landed at an airport to refuel.
The article makes it seem like the airport in question was in Vidin, Bulgaria but according to another article they were observed landing and refueling at an aero club (grass air strip) in Debrecen, Hungary. Five or six occupants got out, quickly refueled the plane with jerry cans, and took off again. Hungarian police got there as they were getting ready to take off again, tried to block them from doing so, but they took off 10 minutes later.
The plane was abandoned at an airport that’s been closed for decades in Bulgaria. Interestingly the Bulgarian airport runway is rented a bit later in the summer by gypsies to dry herbs so probably some local knowledge.
The same article I saw this in says that the Bulgarians have opened an investigation for essentially plane theft so the plane was stolen in Lithuania.
Could be a drug flight or people who really wanted out of Lithuania quickly.
Need to refuel badly enough and the plane will stop on its own.
It was probably a couple of soy-boys trying to make their way to the Ukraine.