The French education minister has defended the use of force to evacuate almost 200 protesting students from the Sorbonne university in Paris.
Gilles de Robien accused some of the students of "odious acts", including defacing books and equipment.
Riot police using tear gas and batons confronted students angry at a new labour law, that would allow employers to hire and fire young workers.
But a student union leader said such tactics would lead to more violence.
The prime minister, Dominique de Villepin, is due to give a nationwide television address on Sunday, in an attempt to quell disquiet over the law, which has provoked several demonstrations throughout France over the past week.
At least two people were injured and there were several arrests in Saturday's operation at the prestigious Sorbonne.
Police stormed the university early in the morning to drive out the students - some of whom had been inside for three days - clearing the main building in less than 10 minutes.
"This is what happens when you call for disorder," said Mr Robien.
Interior Minister Nicolas Sarkozy, who cut short a visit to France's Caribbean Antilles Islands because of the unrest, denied there was any brutality.
One student, 20-year-old Marianne, said: "Police showed violence which went beyond all the limits. People were playing music and they just got attacked in the most incredible way."
But another said: "Their reaction was rather cool and they pushed us calmly to the exit."
Bruno Julliard, president of students' union UNEF, said: "If the government wants to continue using force... then we are heading towards a serious conflict."
The First Employment Contract (CPE), passed by parliament on Thursday, is a two-year contract for under-26-year-olds which employers can break off at any time without explanation.
Ministers hope the flexibility will encourage employers to hire more young people, safe in the knowledge that they will be able to get rid of them if they have to.
The law, which is intended to tackle France's chronic high youth unemployment, is due to come into force in April.
Critics of the legislation say younger workers would have less job security than older colleagues and France's generous labour provisions would be undermined.
The new legislation currently only applies to small firms but some fear it could be misused by larger employers and make it even harder for young people to find a permanent job.