WARSAW, Poland (JTA) — An employee of the museum at the former Majdanek Nazi death camp was one of six men charged with incitement to hatred for hanging anti-Semitic posters in Lublin.

The men were arrested on Jan. 23. Three were arrested at a Lublin bus stop while hanging a poster reading “Zionists out of Lublin” and “Our streets, our houses.” More posters were found in their car.

Another three were arrested in their homes.

The museum employee, identified as Krzysztof K., 50, works in the exhibition department, where he designs book covers and catalogs. Police said at least two anti-Semitic posters were printed on a museum printer.

The men had been putting up anti-Semitic posters since 2010, police believe.

They could face up to 7 1/2 years in prison.