Baton-wielding police on Saturday fired teargas to disperse a demonstration by thousands of jobless Tunisian graduates in the capital Tunis.
Protesters chanted "Down with the government!" and "Work, freedom, dignity", a slogan of the January 2011 revolution that toppled former strongman Zine El Abidine Ben Ali.
Police went on the offensive as the protesters tried to march on the Avenue Habib Bourguiba, Tunis's main thoroughfare.
The avenue has been the location of frequent protests since the uprising that ousted former strongman Zine El Abidine Ben Ali.
But a ban was imposed on March 28 following incidents during a demonstration demanding sharia law.
"Around 20 demonstrators were wounded when police charged," said Belgacem Ben Abdallah, leader of the Union of Unemployed Graduates which called the protest.
"We came to demonstrate peacefully for jobs, freedom and dignity because nothing has changed since the revolution. The police behaved brutally just as in the days of Ben Ali," he said.
The interior ministry said six police officers were injured during the protest by stone-throwing demonstrators.
"They were warned but deliberately ignored the ban to invade the area by force, the police used teargas to stop them, causing clashes," said ministry spokesman Khaled Tarrouche.
"We will not allow chaos and will not permit the law to be trampled over, the demonstrators had a choice of several places where they could have expressed themselves freely," he added.
Abdallah said the protesters wanted jobs and unemployment benefit equal to the minimum Tunisian wage (about 150 euros a month). Unemployment stands at 19 percent in Tunisia, nearly a quarter of whom are graduates.
He accused the government led by the Islamist party Ennahda of "not keeping its promises" and "taking over the policy of Ben Ali" on employment.
"We will not back down an inch on our rights," said protester Hafedh Rays.
"A year and a half after the revolution we are still unemployed, in the same situation and without prospects," said another demonstrator who did not give his name.
The new Tunisian government's job creation programme aims to create 25,000 posts in the public sector, far below the number deemed necessary.
Unemployment was a major factor in the Tunisian revolution which led to a series of uprisings called the Arab Spring and ultimately led also to the fall of Egyptian president Hosni Mubarak, Libyan leader Moamer Kadhafi and Yemen's Ali Abdullah Saleh.© ANP/AFP