A Tunisian court sentenced four people to death and two to life in prison on Wednesday over the jihadist-claimed killing of a secular politician more than a decade ago.

The 2013 murder of then opposition leader Chokri Belaid was claimed at the time by militants loyal to the Islamic State group which would go on to launch a spate of extremist attacks in the country.

His killing dealt a blow to the fledgling democracy established after the overthrow of longtime dictator Zine El Abidine Ben Ali in the first of the Arab Spring uprisings of 2011.

Belaid, 48, was a fierce critic of Ennahdha, the Islamist-inspired party that then dominated national politics. He was killed on February 6, 2013 in his car outside his home.

The North African country is now ruled by President Kais Saied who in 2021 staged a sweeping power grab and outlawed Ennahdha, whose leader Rached Ghannouchi is in jail on unrelated charges.

The court's judgement came after 11 years of investigations and was announced on national television in the early hours of Wednesday following 15 hours of deliberation.

The four defendants sentenced to death were identified by Tunisian media as Mohamed El-Akari, Mohamed El-Awadi, Mohamed Amine El-Kasmi and Mohamed Abdellaoui.

Tunisia still hands down death sentences, particularly in "terrorism" cases, even though a de facto moratorium since 1991 means they are effectively commuted to life terms.

Nineteen others received sentences ranging from two to 120 years behind bars over charges including "belonging to terrorist groups" and "premeditated murder".

Five defendants were sentenced to time already served in other cases.

Deputy prosecutor Aymen Chtiba welcomed the sentences, saying "justice has been done".

  Years of violence 

The years after the 2011 revolution saw a surge in Islamist radicalism in Tunisia with thousands of jihadist volunteers leaving to fight in neighbouring Libya as well as Syria and Iraq.

Jihadist attacks in Sousse and the capital Tunis in 2015 killed dozens of tourists and police, although authorities say they have since made significant progress against the extremists.

Jihadists loyal to the Islamic State group also claimed the killing of another left-wing opposition figure, Mohamed Brahmi, six months after Belaid's assassination.

The killings stirred mass protests and a political crisis in which Ennahdha ceded power to a government of technocrats.

The year after, authorities announced that the suspected mastermind of Belaid's assassination, Kamel Gadhgadhi, had been killed in a counterterrorism operation.

Saied, who regularly refers to Belaid and Brahmi as "martyrs", in June 2022 dismissed dozens of judges, some of whom he accused of obstructing the investigations into the 2013 killings.

Last year, the justice ministry set up a special commission to carry out an "in-depth" study of the police and judicial investigations.

 'First step' 

 Belaid's family and their lawyers have over the past decade accused the Ennahdha party and some judges of hindering investigations into the assassination.

They have charged that Ennahdha, when it was the ruling party, was at least lenient towards extremist discourse following the 2011 uprisings.

The victim's brother, Abdelmadjid Belaid, welcomed the court ruling, saying "it's something we had been waiting for".

He spoke to AFP while surrounded by left-wing demonstrators who have gathered weekly in Tunis demanding the truth about the killing.

The brother said it was "a first step set in the right direction" but told AFP he would continue his "fight", in particular against "the manipulation of the case".

"These are only some of the perpetrators," he said, adding that "soon, in another case, there will be others who have a direct relation with Rached Ghannouchi".

The rulings didn't establish any links with the political party.

A few hours after the verdict, Zouhaier Ben Abdallah, the public prosecutor at the Tunis court where the ruling was issued, was dismissed without any explanation being given, according to local reports.

Ennahdha had pushed back against the accusations at the time of the killing, having blacklisting the Salafist movement Ansar al-Charia -- which it initially tolerated in the years after 2011 -- as a terrorist organisation.

In a statement it released Wednesday on Facebook, the Islamist-inspired party welcomed the conclusion of the Belaid trial as a vindication of its repeated denials of any wrongdoing.

It said the court had concluded "with certainty the innocence of the Ennahdha movement", despite "a desire among certain ideological currents and political parties to make false accusations".