A young Tunisian who set himself alight last month in a protest over unemployment, sparking a wave of unrest and clashes, has died in hospital, his relatives told AFP Wednesday.

The death on Tuesday of 26-year-old university graduate Mohamed Bouazizi, who doused himself in petrol and set himself alight nearly three weeks ago, was also announced by Paris-based rights groups.

"Mohamed died yesterday (Tuesday) at 5:30 pm at the hospital in Ben Arous," said his brother Salem Bouazizi. He would be buried on Wednesday, he said.

"It is a tragedy. The whole family is united at Mohamed's family home to wait for the arrival of the body," his uncle Mehdi Horchani added.

Despite his education, Mohamed Bouazizi was forced to sell fruit and vegetables on the street in the Sidi Bouzid region of central Tunisia to earn a living.

After police confiscated his produce because he did not have a proper permit, he burned himself in protest on December 17, rights groups said.

Unrest and clashes erupted across tightly-controlled Tunisia, with a teenager shot dead by security forces in one protest, several people wounded and cars and buildings set alight.

The Paris-based International Federation of Human Rights Leagues, announcing Bouazizi's death, said the underlying causes of the unrest should be looked into.

"An investigation or a national commission is needed to determine the causes and the solutions of this social protest which has taken a tragic form," said the leader of the group, Souhayr Belhassen.

"We have learned of the death of young Mohamed Bouazizi in the Ben Arous hospital from serious burns," the Committee for the Respect of Freedom and Human Rights in Tunisia said in Paris separately.

The health ministry also announced his death in a statement on the official TAP news agency that recalled that President Zine El Abidine Ben Ali had visited Bouazizi in hospital late December.

On December 22 another young man, Sidi Bouzid, climbed up an electricity pylon and electrocuted himself on the cables, saying he was fed up with being unemployed.

The government would not confirm the suicide, but ordered a judicial investigation into the circumstances of his death.

The worst day of the rioting was December 24, when thousands of people took to the streets and burned the local headquarters of the national guard, which responded with gunshots that killed an 18-year-old protestor.

Protests spread to the capital Tunis in late December.

The latest clashes were on Monday when security forces fired tear gas to disperse a march of mainly high school students in the western town of Thala, a union member and witness said.
The march of around 250 people turned violent when police fired teargas to disperse the group and one gas canister fell into a mosque, a witness said.
Demonstrators responded by setting alight tyres and the local offices of the governing party, the Constitutional Democratic Rally.
Ben Ali has said he was concerned by the tensions but also accused the opposition of exploiting the situation and exaggerating the scale of the protests, and foreign media of dramatising events.
He sacked three government ministers and the regional governor of Sidi Bouzid, as well as other regions, as the unrest continued.
Civil groups and the opposition in Tunisia say the protests are driven by high unemployment and high prices of raw materials and have called for radical reforms.
Tunisia's unemployment rate is officially 14 percent, but the percentage of graduates without work is about double that, and has prompted a warning from the International Monetary Fund.