Students in the German state of North Rhine-Westphalia stormed the regional parliament in Dusseldorf last week in protest at plans to introduce student registration fees and penalty fees for long-term students.
More than 2,000 students broke through police barricades chanting "Clement Out", referring to state premier Wolfgang Clement, who wants to introduce student fees against the will of his political ally chancellor Gerhard Schroder.
As temperatures soared to 35C, tempers flared and 21 students were arrested. The demonstrators dispersed after two-and-a-half hours.
It was a high point of weeks of demonstrations in the state, which has half-a-million students, more than any other German region.
Students are angry at the SPD-Green state government's plans to charge €50 (£32) re-registration fees per semester to returning students as well as €650 per semester for "slow-lane" students who have taken more than 14 semesters to complete their degrees.
The protests appear to be paying off. Harald Schartau, the state's SPD party leader, said: "As far as I am concerned, the issue of registration fees is totally off the agenda." But Mr Schartau wants to stick to plans to charge slow-lane students.
Some 155,000 students in North Rhine-Westphalia are in at least their 15th semester; 4,500 of them have exceeded 20 semesters.