SIdi Bouzid, Tunisia: Thousands of Tunisians rallied on Saturday to commemorate a young fruitseller's desperate gesture a year ago which unleashed the pioneering revolution of the Arab Spring.

Newly-elected President Moncef Marzouki joined the crowds in the town of Sidi Bouzid, where Mohamed Bouazizi's altercation with a policewoman and his subsequent self-immolation set off a wave of protests that toppled long-standing dictators and dramatically changed the Arab world.

"Thank you to this land, which has been marginalised for centuries, for bringing dignity to the entire Tunisian people," said Marzouki, who was sworn in as president this week after the country's first post-revolution election.

"Our role is to bring back the joy of living which had been stolen by despots," Marzouki said.

Bouazizi, an unemployed graduate, set himself on fire on December 17 last year after a row with a policewoman, to protest abuses under the 23-year regime of president Zine el Abidine Ben Ali -- sparking a revolt that ousted the strongman less than a month later.

The fruitseller committed his desperate act in Sidi Bouzid, part of the neglected Tunisian interior long overlooked for investment by the former regime in the north African country, which held its first free elections in October.

From daybreak Saturday, Tunisians swarmed into Sidi Bouzid, where the streets were decked with Tunisian flags, pictures of "victims of the revolution" and a giant photograph of Bouazizi.

"I look around me and see many young people in the crowd who braved the bullets of Ben Ali's police last year to defend the values of freedom and dignity," human rights activist Sabrine Ammari told AFP.

A monument representing Bouazizi's street stall surrounded by wheelchairs symbolising ousted Arab dictators was unveiled to applause, while union leaders, rights activists and members of the new constituent assembly took to the microphone.

The popular uprisings that spread from Tunisia across the Arab world in 2011 led to the ouster of Ben Ali as well as the leaders of Egypt, Libya and Yemen, while deadly anti-regime protests continue to convulse Syria.

Ben Ali was ousted on January 14 and went into exile in Saudi Arabia but is the subject of 18 trials in Tunisia on a string of charges including murder and destabilising the state, embezzlement, fraud and abuse of power.

He has already been sentenced to 66 years in prison in total, and also has an international warrant out on his head.

Tunisia's newly-elected constituent assembly -- dominated by the moderate Islamists of Ennahda -- on Monday elected former opposition leader Marzouki as president.

Prime minister-designate Hamadi Jebali, Ennahda's number two, is preparing to form a government which faces the challenge of creating jobs and developing the long-neglected interior regions of the country.

In Sidi Bouzid, demonstrators voiced their pride at Tunisia's pioneering role in the Arab Spring but also their frustration that the promise of the revolution has yet to bear fruit.

"Nothing has been achieved yet. No jobs have been created and there has been no social or economic develop," said unemployed 28-year-old Moncef Dridi. "The young people who understood Bouazizi's gesture are impatient."