One of the sources said that two Mirage 2000D combat jets and a tanker aeroplane took off before 1230 GMT.

A second source said their presence was "no longer justified after the end of the deal".

"France is putting an end to its detachment of fighter planes at the Kossei airbase in N'Djamena. The French army has taken the decision to remove its planes," the source said.

Chad had been a key link in France's military presence in Africa and its last foothold in the wider Sahel region after the forced withdrawal of its troops from Mali, Burkina Faso and Niger in the wake of a series of military coups.

But it announced on November 28 a decision to end a defence accord with Paris mainly dating from independence in 1960.

France until then had about 1,000 troops in the country.

France has been forced since 2022 to remove troops from Mali, Burkina Faso and Niger after military takeovers that have seen the countries become closer to Russia.

Chad's leader General Mahamat Idriss Deby has also sought closer ties with Moscow in recent months but talks to strengthen economic cooperation have yet to bear concrete results.

The landlocked nation faces a potent threat from Boko Haram and other militant groups.