Belgian riot police on Tuesday clashed with striking prison guards holding a demonstration at the Justice Ministry.

The baton-wielding police entered the ministry building forcing out dozens of the prison guards gathering in the lobby, Belgian media reported.

According to a video on the website of broadcaster VTM, police even doused some demonstrators with what is reported to be pepper spray.

About a thousand demonstrators had gathered in support of the warders outside the ministry headquarters in the capital, Brussels, throwing eggs at the facade of the building, setting off firecrackers, chanting slogans and protesting budget cuts, according to the media.

The incident raised tensions in an already critical situation caused by the warders’ strike that started three weeks ago.

The warders, who are discontent over pay and labor conditions, had originally planned to go on a 24-hour strike.

However, the strike got extended and the government sent in army troops, regular police forces and Red Cross workers to run jails.

The government is now facing legal complaints from prisoners and human rights groups for inmates being denied of their basic rights and amenities.

"The inmates can't go out, they are stuck in their cells all day, they aren't getting fresh air, the bed sheets aren't getting changed, they are not allowed any visits," Vincent Spronck, governor of Brussels’ Forest Prison, was quoted by media as saying last week.

Alexis Deswaef, a lawyer and president of Belgium’s Human Rights League, recently said that “detention conditions have become completely inhuman ... [and] prisoners have resorted to smashing up furniture and starting fires in protest.”

"This sets a dangerous precedent - to use the army to sort out a social issue," Deswaef said.