If this is anything like the Belarus situation (which I assume) then people were brought there on the promise of getting into the EU and, when that didn’t materialise, weren’t given the opportunity to leave Russia via any other means: They were bussed to the EU border and told to walk towards it and worse:
A group of Yazidi migrants complained to reporters that they were beaten by Belarusian border guards when they tried to return to Iraq after an unsuccessful attempt to sneak to Poland. The guards, according to these people, forced them to stay on the border.
Also:
Belarusian authorities refused to accept the Polish humanitarian aid intended for migrants who got stuck on the Belarusian-Polish border at least twice, in August and October.
Reactions, btw, included Iraq and Turkey suspending flights to Belarus.