Tens of thousands of students protested in around 40 Italian cities on Friday against compulsory internships for high school students.
As with the first nationwide protests on January 28, there were riots again on Friday.
At least four police officers were injured in Turin when the partially masked students tried to storm the headquarters of the employers' association Confindustria.
The Ministry of the Interior had put the police in numerous cities on alert for fear of renewed riots.
The protests were triggered by two accidents at work in which two schoolchildren aged 18 and 16 died within a month in the regions of Friuli Venezia Giulia and Marche.
Since the school reform of 2015, grammar school students have been obliged to do 90 to 180 hours of work placements during the last three years of school, depending on the type of school.
The students demand the abolition of the internship requirement and better protection for students doing internships.
The student protests are also an expression of the widespread lack of prospects for young people in Italy's economic and social life.
In no other country in the euro zone are there so many young people who are not attending university, training or working.
Youth unemployment is almost 30 percent nationwide, and 60 percent in some provinces in the economically weak south.
A major point of contention is also the Abitur, which Education Minister Patrizio Bianchi wants the students to take again as they did before Corona - namely with written instead of oral exams.
The young people criticize that they are not prepared after months of distance learning.