German authorities say they've arrested three right-wing extremists and seized several kilograms of powerful firecrackers the suspects might have been planning to use in an attack to cause fear at asylum-seekers' homes.

Interior Minister Thomas de Maiziere said Thursday on a visit to a home for asylum seekers from the Balkans in Bamberg that initial evidence indicates authorities "might have prevented attacks or other crimes," the dpa news agency reported.

The three were arrested Wednesday evening in a series of raids on 12 locations, Bavarian Interior Minister Joachim Herrmann said.

Authorities said items seized included several kilograms of illegal fireworks, some of which were powerful enough to blow out windows.

An anti-immigrant demonstration is planned for later this month in Bamberg, but authorities are trying to ban it, dpa reported.