Nineteen officers were taken to hospital with minor injuries and two students were arrested after a second day of clashes between police and protestors in Turin on Tuesday.
The violence broke out during a student demonstration protesting a meeting of university chancellors linked to Italy's programme for this year's Group of Eight summit.
The injuries occurred after students tried to break through a police cordon surrounding the meeting venue and police charged the demonstration in response, letting off teargas in the process.
The demonstration, which followed a similar protest on Monday, broke up not long after.
Seventeen police and two Carabinieri officials were treated for minor bruising and the after-effects of teargas.
Two of the protestors, thought to be students from Milan, were arrested during the clashes although it is not clear whether they have been charged.
One man was charged with resisting arrest and injuring a public official after Monday's events, while two protestors and a policeman were taken to hospital.
Tuesday's demonstration broke up quickly but came under heavy fire from police unions and centre-right politicians, who blamed students for the violence.
Government Programmes Minister Gianfranco Rotondi expressed his solidarity with the police, describing what happened as ''unjustified scenes of violence''.
The spokesman for Premier Silvio Berlusconi's People of Freedom party, Daniele Capezzone said ''leftwing extremists'' were behind the clashes.
''This violence is the latest evidence that the left is no longer able to stem the flood of extremism or the temptation to resort to violence as a political tool,'' he said.
Police representatives also expressed their anger at the day's events.
''It was easy to predict what would happen today and now we are struggling to explain to our injured colleagues that they must continue safeguarding public security without suitable protection,'' said union chief Nicola Tanzi.
He called for higher wages, greater police powers of arrest and tougher penalties for those who injure officers.
The leader of the UGL police union Cristiano Leggeri said his members were ''deeply concerned'', particularly in view of this summer's G8 summit, which he predicted would see much worse scenes of violence.
However, the trade union umbrella, RDB-CUB, a grassroots movement, condemned the police action as ''repression of alternative views expressed by students and workers''.
Although no opposition politicians defended the violence, Democratic Party Senator Vincenzo Vita stressed the importance of ''continuing to dialogue with students, trying to understand the problem''.
The chancellor of Turin Polytechnic, Francesco Profumo, who helped organize the meeting of chancellors, also said the violence was a sign that there had been ''a serious breakdown in communication somewhere''.
''This tells us we need to change our communication strategy,'' he said.
The conference, attended by 41 chancellors from 19 industrialized and developing countries, focused on economics, ethics, energy and ecology in the context of sustainable development.
No politicians or ministers were present at the event, which wrapped up with a final statement for consideration by G8 leaders at the July summit of leaders, taking place in L'Aquila.
The declaration, which incorporated calls from a similar conference of students from around the world in May, called for a more efficient use of resources and said ethics should steer policy decisions. It also called for a greater focus on renewable resources and energy saving, in order to tackle climate change.
