The tunnel is a closed system if you block each entrance with troops.
Then capture each person in the tunnel.
Photograph
Fingerprint
Obtain DNA Sample
Deport them out of Europe.
Classify them as never accessible to Europe again.
Any civil unrest should result in the same fate.
If an uprising occurs, put it down and start deporting en mass.
Europe needs to pull it’s head out...
While we’re on the subject, so does the U. S.
I would add cut off their right hand so they must do everything with their "unclean" hand.