There have been dramatic scenes in Brussels, with striking prison wardens bursting into the Belgian Justice Ministry building.
Baton-wielding riot police had to force them out.
There were scuffles inside the building and police used what appeared to be pepper spray.
The justice minister has condemnation the intrusion.
“Two ladies from the reception desk are still in shock. I spoke with them for a long time. They felt personally threatened,” said Koen Geens.
“Fortunately, there was no physical violence, but the protesters cause a lot of damage downstairs. The Justice Ministry building won’t be accessible for several days.”
The incident has hiked tensions in a three-week strike over pay and conditions. The government has had to send in troops to help run jails.
Prisoners have also complained that they are being denied access to basic amenities.