Masked rioters looted shops in central Frankfurt late on Saturday after largely peaceful daytime demonstrations over the cost of living turned violent.

Police said windows of several shops were smashed and Molotov cocktails were thrown at emergency personnel, prompting the closure of a large section of the city's main shopping street and the deployment of special police units.

According to AFP, a gun store was among the shops targeted, with police arresting a suspect and seizing two weapons, while Bild reported a trainer shop and a perfume store were also hit. Police said the situation calmed down overnight into Sunday.

The violence was not confined to Germany's financial hub.

In Cologne, police said officers were attacked near the main train station with bottles thrown and even a bicycle launched, and used water cannon; police chief Johannes Hermanns said it was 'deeply saddening' that peaceful young demonstrators had been infiltrated by extremists.

In Berlin, an evening demonstration left 27 police officers injured with up to 56 people temporarily detained, while in Hamburg people dressed in black set barricades on fire — NDR reported 120 arrests there. AFP says several police officers were injured in the nationwide violence.

The movement protests underfunded schools, the high cost of living, public spending cuts, sharply increased military spending and plans around military service that it fears could bring back conscription.

Spokesperson Lina Friedrich said the demos were 'to fight for peace and freedom, rather than for war and coercion.' The movement explicitly rejected violence, saying extremist groups and hate speech have no place in it.

Turnout fell short of expectations even before nightfall.

Organisers had expected around 180,000 participants and claimed roughly 120,000 took part, according to AFP, while authorities in Frankfurt, Munich and Berlin reported as many as 18,000 protesters — roughly half what organisers estimated on their website.

Hesse's interior minister Roman Poseck said 'around 100 clearly identified left-wing extremists' had infiltrated the Frankfurt protest, calling it 'shameful' how the event ended and warning that France must not be held up as a model.

Berlin has been in contact with French and Italian officials over fears radicals could travel to join the protests.

The German unrest landed on the same weekend as a third consecutive Saturday of French demonstrations, with more than 320,000 people protesting nationwide, including 70,000 in Paris, per the French Interior Ministry.

France deployed 70,000 police, and authorities reported more than 560 arrests by Saturday night after clashes in Toulouse, Lyon and Marseille; Interior Minister Laurent Nuñez said an officer was injured by a Molotov cocktail.

Protests also hit Rome, Turin, Brussels and Lisbon, where Portuguese riot police cleared a housing-protest tent camp. Young demonstrators have now marched in France, Belgium, Ireland, Spain, Portugal, Italy, Greece, Serbia and Albania.

The movement's grievances — housing, education quality, public service cuts and the burden of military spending — show no sign of easing, and organisers have signalled solidarity with parallel waves in France and Italy.

Prime Minister Luis Montenegro ruled out scrapping Portugal's contested rental bill but said he is open to amending it before a final vote in coming weeks, and Portugal remains among Europe's worst housing crises, with house prices more than doubled since 2017 per Reuters via the Hindustan Times.

In France, Nuñez has pledged an 'extremely firm response' to any trouble and banned demonstrations from city centres where disorder is a risk.