Chad's main opposition parties on Wednesday denounced what they called an "institutional coup d'etat" after the shock death of newly re-elected president Idriss Deby Itno and his replacement by son Mahamat.
Around 30 opposition formations "call for the installation of a transition led by civilians... through inclusive dialogue," the parties said in a statement.
They called on Chadians "not to obey illegitimate decisions" by the transitional military council including the naming of Mahamat as Deby's successor, a curfew and border closures.
Among the main signatories were the party of Deby's historic rival Saleh Kebzabo and Success Masra, another of his fiercest critics.
The opposition groups also warned former colonial power France, which had backed Deby since he came to power on the back of a 1990 coup in the poor Sahel country, "not to meddle in Chad's internal affairs".
They also called on the international community to "help the Chadian people restore the state of law and democracy".
Major powers not critical of army takeover
The national funeral of Idriss Déby Itno will take place on Friday in N'Djamena, in the presence of French President Emmanuel Macron. Ten other heads of state are also expected to attend, including several from Sahelian countries such as Mali, Niger and Burkina Faso. The head of European diplomacy Josep Borrell has also announced his presence.
"The transition announced must be limited, take place peacefully, with respect for human rights and fundamental freedoms, and allow the organization of new inclusive elections," Borrell warned in a statement.
The United States on Wednesday called for a "peaceful and democratic transition" to a civilian government in Chad, without going so far as to condemn the military junta's seizure of power.
Paris was equally mute.
"The potentially explosive consequences of the death of President Idriss Déby cannot be underestimated, both for the future of Chad and for the region," Human Rights Watch noted Wednesday. "Chad's regional and international partners should closely monitor the situation and use their influence to prevent abuses against civilians," the NGO said.
Especially since the transition period can be extended once, according to the new charter.