BRATISLAVA, Slovakia (AP) — Unknown vandals have damaged dozens of gravestones at a Jewish cemetery in northern Slovakia, police and a group that worked to preserve the site said Tuesday.

The Remember group said 59 gravestones were knocked down and damaged at the cemetery in the town of Namestovo.

Slovakia's Jewish community called it “an unprecedented barbaric act.”

The cemetery that dates to the second half of the 18th century had been badly neglected for decades before the organization started its renovation in 2010.

Police said they were investigating the attack.

Remember chairman Karol Kurtulik said his group will persist with its effort to preserve the site.