VIENNA (AP) — Police say a demonstration protesting a right-wing ball in Vienna ended with 20 detentions and four people slightly injured.

About 3,000 demonstrators gathered to oppose the ball being hosted at the Hofburg palace by the right-wing FPO party, which promotes xenophobia and has some neo-Nazi supporters.

Some tried to break through police barricades and a few threw paint bombs and tear gas canisters. They dispersed early Saturday.

The demonstrators said the guests include neo-Nazis and other rightist extremists from Austria and abroad.

Two demonstrators and two police officers were reported slightly hurt.