The sudden death of Chad's president, Idriss Deby, this week has raised concerns about the country's stability and the joint fight against regional terrorist groups, like Nigeria's Boko Haram. Nigeria and Chad have long been allies against Islamist insurgents, but analysts say Deby's death could complicate the picture.
A state funeral held Friday in the capital, N'Djamena, was attended by many heads of state, including Nigerian President Muhammadu Buhari, despite warnings from rebel groups threatening attacks.
Earlier in the week, Buhari tweeted, "I am deeply shocked and devastated."
President Idriss Deby died Monday, suffering from wounds he sustained while visiting frontline troops battling rebels in northern Chad.
His sudden death raises concerns of stability in Chad and in the wider Sahel region, where Chadian troops contribute significantly to the fight against insurgent groups.
Political analyst Rotimi Olawale said troops could be shifting focus to domestic issues first, and not regional security.
"The first focus of the Chadian government will be consolidating power in Chad and therefore I will not be surprised that in the immediate term the focus will be on domestic security within Chad," Olawale said.
Last year, Nigeria, Chad and Niger started a joint operation to eliminate terrorist groups Boko Haram and its Islamic affiliates.
Security expert Kabiru Adamu worries that Deby's death could stall regional security progress.
"Gaps will be created and these are the gaps that will likely lead to an escalation of the current security situation in several parts of the Sahel region,” he said. “Chad under president Deby was a stabilization force. What will happen in the long term is a bit uncertain."
But Olawale said other regional forces must work together to prevent an uptick in violence.
"We hope that the regional actors especially Nigeria, Cameroon, Niger, Chad continue to work together to ensure terrorist groups do not explore loopholes within the security architecture," he said.
Nigeria this week beefed up border security to prevent an influx of people from Chad, said the country's defense minister.
The 68-year-old Deby ruled Chad for 30 years and was re-elected to a sixth term in office just days before his death.
Chadian military authorities ignored the constitution and appointed his son, Mahanat Idriss Deby, to lead a ruling council for 18 months, until a new government is elected.