German leaders have promised a tough response after riots and looting in the city of Frankfurt over the Halloween weekend, tagesschau and CNA report. About 100 police officers were hurt, and 54 people were arrested, the outlets report.

Police said the people arrested were between 13 and 29 years old, tagesschau reports. One officer was badly hurt after being hit by a stone. Rioters threw fireworks and firebombs, and a gun shop was among the stores hit, the outlet says. CNA reports that 17 stores were damaged and five were looted. About 1,300 officers were on duty.

The violence followed mostly peaceful protests by young people from the group Gen Z regelt earlier in the day, tagesschau reports. The group said it had nothing to do with the violence and plans new protests in three weeks.

Hesse's interior minister, Roman Poseck, called it a "horrific excess of violence," tagesschau reports (translated from German). "Things cannot go on like this," he said, according to CNA. Poseck said there were 1,000 to 1,500 troublemakers, most of them from migrant backgrounds. But most of the people arrested are German citizens, tagesschau reports.

Frankfurt's mayor, Mike Josef, said he did not care what passport anyone held, tagesschau reports. Germany's interior minister, Alexander Dobrindt, promised severe penalties, CNA reports. He said troublemakers from immigrant communities had acted together with far-left extremists. CNA says he did not give evidence for that claim. Border checks have also been tightened, the outlet reports.

Police filed 87 criminal complaints and ordered 1,225 people to leave the area, tagesschau reports.

What we know: The riots left about 100 officers hurt and led to 54 arrests.
What we don't: Who planned the violence, and what new steps the government will take.