Protesters threw stones and tomatoes and booed Tunisian leaders off the platform on Monday at a ceremony marking two years since the start of an uprising that changed regimes around the Arab world.
Tunisian President Moncef Marzouki and other dignitaries who spoke had to be escorted off stage by security forces as 3,000 people protested against lack of action by the country's Islamist-led government.
Mr Marzouki said he had no "magic wand" to bring down unemployment.
But protesters complained they have seen little improvement in their region since the new government took power.
Some held signs saying: "The people want the fall of the government and a new revolution."
In recent weeks, Tunisia's stagnant economy has fuelled a face-off between the Islamist ruling party Ennahda and the country's main trade union, with days of rioting.
Ennahda condemned the protest, saying that unrest would only scare off investment in the region.