Activists have once again occupied rooms at a Berlin university in support of the Palestinians and in protest against Israel.
The police and a dpa photographer initially spoke of around 50 people who were at the Institute of Social Sciences at Humboldt University from Wednesday afternoon.
A further 250 to 300 young people demonstrated on the street outside.
A police spokesman said that they were in close consultation with the university. A university spokeswoman said that the situation was being monitored for the time being.
In a statement, the activists of the group called Student Coalition Berlin accused Israel of "genocide" and "ongoing mass murders." It was about "unconditional solidarity with the Palestinian people."
The activists called on the university to accept their occupation and presence and to ban a police operation.
Alongside the Free University (FU) and the Technical University (TU), Humboldt University is one of the three major universities in the German capital.
An occupation of rooms at the FU by the group Student Coalition Berlin was recently cleared by the police.