The death of Yaya Dillo - the main rival to transitional Chadian president Mahamat Idriss Déby in upcoming elections in May - has deepened the political strife plaguing the country.
The European Union and Human Rights Watch have called for an international investigation into Dillo's death, which his party has labelled an assassination.
During a visit to Paris last Tuesday, Chadian Prime Minister Succes Masra said he had agreed to the probe.
Presidential elections in May and June are meant to assure the return of constitutional rule to Chad, three years after military authorities seized power in a coup led by Déby.
However, Dillo's killing during a shoot-out at his party's headquarters last week has thrown a dark shadow over the polls.
While the junta says Dillo fomented an attack against Chad's main security agency, his Socialist Party Without Borders (PSF) party maintains that he was murdered.
'Culture of death'
Even if calls for an international investigation are answered, experts say it is unlikely any conclusions will be drawn.
"A similar situation occurred in October 2022 after the deadly repression of protests, but the report is still not accessible," African specialist Roland Marchal told RFI.
"The history of Chad is full of similar situations, from 1993 or 2008 for instance. Idriss Déby already had opponents killed and no one was ever arrested or punished."
Observers have denounced the culture of impunity in the country, fearing that the opposition is now condemned to lose the election.
RFI's Jean-Baptiste Placca, who covers Africa, has described the situation as a "depressing culture of death".
Opposition politician Max Kemkoye agrees. "We are candidates for death. The tension is already here, troubles are here. It is an explosive cocktail," he told told RFI.
Prime Minister Masra told RFI the government was committed to carrying out an international-style investigation that would "identify responsibilities at all levels".
Rocky road to elections
Déby, announced his intention to contest the 6 May presidential poll three days after Dillo's death.
Déby is the son of veteran leader Idriss Déby Itno, who ruled Chad with an iron fist for more than 30 years before being killed by rebels in 2021.
His son took power in a coup, and later promised elections after a transition period of 18 months.
But his regime has extended the transition by two years, authorising him to run in the presidential and parliamentary elections.
"The election might be an easy win for Déby," Marchal says.
"As his father before him, he will probably praise the people for the high participation rate, and France or the EU will remain silent, because stability in Chad is valuable.
"The double standards with other African regimes is obvious and it renders the EU less and less credible in central Africa and in the Sahel."
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Regional ally
Déby's military government is one of several juntas in power in west and central Africa, where there have been eight coups since 2020.
Chad has long been a key partner for the UN and Western powers in the Sahel in the fight against terrorism, and is one of the last countries still hosting French troops in the region.
Recently Chad was forced to accept the dissolution of the G5 Sahel force after key members Mali, Niger and Burkina Faso cut ties with France and left the group.
Prime Minister Masra met with his French counterpart, Gabriel Attal, on Tuesday in Paris to discuss future cooperation between the two nations.
