KIEV, Ukraine (AP) — A top European human rights official is condemning an attack on a Roma camp in western Ukraine that left one person dead and four others injured, including a 10-year-old boy.

A group of teenagers burst into a small Roma camp Saturday night on the outskirts of the city of Lviv, tearing down tents, destroying property and charging at residents with knives. Authorities are referring to the perpetrators as "radically-minded," a euphemism for ultra-right.

Police have arrested seven men aged 16 and 17 suspected of carrying out the attack and a 20-year-old man suspected of organizing it. The incident was the third attack on Ukraine's minority Roma community in recent months.

Dunja Mijatovic, the Council of Europe's human rights commissioner, says Monday on Facebook that "we cannot allow impunity for hate crimes to prevail."

This story corrects that Mijatovic is not a European Union official.