Rebels who launched an offensive in northern Chad, sparking clashes that claimed the life of veteran president Idriss Deby Itno, are in flight, the country's new defense minister said on Thursday.

The group known by their acronym as FACT has been repelled after fighting along the border with Niger about 300 km north of the capital N'Djamena, Brahim Daoud Yaya said.

"We have routed these terrorists, some of their leaders have fallen on the battlefield, some are fleeing so we are going after them, some have been lucky enough to get back to Libya.

"The police are in the full sweep in the area of ​​operation. Most of the prisoners are in the hands of the gendarmerie and well treated," the defense minister said.

The FACT rebellion has been based in the south of Libya since its creation in 2016.

"Libya is the stronghold of terrorists," said the Minister of Defense, but "I cannot accuse Libya of supporting terrorists as there is no state in Libya".

Fighting erupted in the South of Chad after the group launched attacks on April 11 -- the day of the presidential election -- which killed president Idriss Deby, who was visiting the frontlines.

Deby's son Mahamat Idriss Déby took the reins of the country at the head of a Transitional Military Council, which says it will hold elections in 18 months.

The army had assured, the day before the announcement of the death of Marshal Deby, to have killed 300 FACT rebels and 246 others were captured and referred to the N'Djamena prosecutor's office, according to authorities.

Fighting continued in the Nokou area, in the Nord-Kanem department. Last week, a Chadian army helicopter crashed there, following a "technical failure" the army assured, FACT claimed it had shot down the aircraft.