French authorities expressed relief Sunday after mass protests over rising living costs resulted in less violence than previous weekends. But police expect new demonstrations as high schools at the heart of the movement reopen Monday after their autumn break.

Violent protests in Germany are the work of leftists and migrants, the country’s interior minister has said.

The protests were organized by a group known as “Gen Z regelt” — loosely translated as “Gen Z sorts things out” — which had stressed in the run-up to Saturday’s mass gatherings that it wouldn’t tolera...