Berlin  - A mounting crisis at German universities, where the government and professors blame one another for overcrowding and student stress, boiled over Tuesday into street demonstrations.

Students are angry that courses which used to last five years are being compressed to three, without much reduction in what they have to learn. They also object to the introduction of tuition fees.

Police in the south-western city of Freiburg said 5,000 students and school pupils marched through the streets. Other cities with big rallies included Berlin and Cologne.

German universities are entirely funded by the 16 state governments, and charge only token tuition fees or none at all.

Statistics from the Organization for Economic Cooperation and Development (OECD) have suggested Germany does not serve students well. Undergraduate students often complain that they rarely even meet one on one with the professors, who have life tenure.

Unlike protests in the 1960s and 1970s, the protests, which began last month with occupations of lecture halls, are focussed on the problems of the overcrowded universities, not of society.

The state governments and professors have said the students are right, but each blame one another for the crisis.

Banners carried by the protesters included the ironic "Welcome to Factory Learning" and "Can't afford education. Can't afford stupidity either."

Under European Union prodding, Germany and Austria agreed 10 years ago to introduce courses lasting three years to confer bachelor degrees, in place of four or five-year courses to confer a diploma.

But students say professors, who opposed the changes in a centuries-old academic tradition, have refused to rejig course content, now set far more exams and made the system worse.

Government officials are urging universities to scrap unnecessary classes and allow students four years to do a bachelor degree, while the professors are demanding a big increase in state funding.(dpa)