Anti-capitalist protesters vowed Monday to occupy public spaces across Hamburg with tents, as tensions with police rise days before the German city hosts a G20 summit.
On Sunday police used pepper spray as they cleared tents set up by some 600 activists on the banks of the Elbe river in scuffles that saw at least one protester injured.
More than 30 demonstrations have been scheduled in the days before and during the two-day Group of 20 summit that starts Friday, guarded by almost 20,000 police.
Protest organisers and the northern city-state of Hamburg have for weeks sparred in the courts over whether activists could set up tent cities with portable toilets, showers and kitchen facilities.
Courts have found that, while such a protest camp would in principle be a legitimate political demonstration, police had the right to prohibit overnight camping on public lands.
Activists calling themselves the "enraged groups of resistance against the G20" charged that police were unjustly characterising camps as retreats for militants in order to "criminalise legitimate protest".
In a posting on left-wing website indymedia, they warned that if they weren't granted the right to camp by early Tuesday, they would "massively occupy parks, open areas and transport hubs of the city".
Police say they expect up to 8,000 extreme left-wing militants likely to use violence during the protests.