Tunisians who won the Nobel Peace Prize are joining with townspeople in the country's beleaguered heartland to mark five years since a desperate street vendor set himself on fire, unwittingly setting in motion upheaval across the Arab world.

Tunisia is the only country to have emerged with a budding democracy, but it's grappling with the threat of violent Islamic extremism, now ravaging the region from neighboring Libya to Syria.

Nobel winners are expected to take part in a ceremony Thursday in Sidi Bouzid, the epicenter of Tunisia's revolution, where fruit vendor Mohamed Bouazizi set himself afire on Dec. 17, 2010. The gesture unleashed protests by poor and frustrated Tunisians that forced out an autocratic ruler and sparked uprisings elsewhere.

Five years later, though, Sidi Bouzid residents are still struggling.