Campaigners took over the Examination Schools - buildings used for lectures and where students take exams - in defiance of the university authorities and to publicise their belief in "education free at the point of delivery".

Student leaders estimated that 140 people took part in the protest, while the university put the figure at 60 to 70.

Students want the university to tell the government to withdraw tuition fees

A statement from the students, who took over the building at 2pm on Monday, said: "We believe that education has an inestimable value in itself; that it is not a commodity with a market value."

The students ended their protest at 9am on Tuesday, and have said that lectures will now be allowed to "continue as normal".

To keep supporters informed of developments in the campaign against fees, the students are using the Oxford University Student Union's Internet site to provide news.

The occupation followed a march through the streets of Oxford last week which supported a campaign of non-payment of tuition fees by first-year students at the university.

Five students refused to pay their £1,000-a-year tuition fees, but the university now says they have agreed to pay rather than face expulsion.

The students who occupied the buildings said the introduction of tuition fees was an attack on the principle of free and equal access to university education.