Several suspected Boko Haram fighters have blown themselves up during a police raid in N'Djamena, Chad's capital, killing five officers and six of the fighters, police and government officials have said.

Monday's raid on an illegal arms cache was part of a security operation aimed at dismantling a network of Boko Haram blamed for twin suicide bombings in N'Djamena earlioer this month.

"After an interrogation, a suspect showed us a house for building bombs," said Interior Minister Abderahim Bireme Hamid.

"When we arrived on the scene at 5am our forces came across the ... terrorists who blew themselves up."

The raid follows a June 15 double suicide bombing which killed at least 33 people in N'Djamena in the deadliest attack of its kind in the city.

Before Monday's raid in the capital, Chad's chief prosecutor announced "the dismantling [of a Boko Haram cell] and the arrest of 60 people" as part of an inquiry into the suicide bombings.

At least 33 people were killed in the deadliest ever attack in N'Djamena [Reuters]

"A terrorist cell was identified and taken down. Sixty people were detained," including Nigerians, Chadians, Cameroonians and Malians, prosecutor Alghassim Kassim said.

Kassim said that one of three people behind the June 15 attacks - all killed in action by security forces - had been positively identified, while the identity of the two others was being checked.

Chad has played a leading role in helping Nigerian forces win back territory from Boko Haram, which has mounted a six-year insurgency to create an area governed by Islamic law in Nigeria's northeast, and attacked neighbours Niger and Cameroon.

N'Djamena is a command centre for a regional force in the fight against Boko Haram, grouping troops from Nigeria, Chad, Cameroon and Benin, as well as a base for a 3,000-strong French operation tackling fighters in the region.

Despite territorial setbacks in recent months, Boko Haram has shown its ability to strike back in the Lake Chad region in a series of attacks in Nigeria, Niger and Chad.

On Sunday, Chadian troops stationed in neighbouring Cameroon killed "eight Boko Haram elements" in a raid into Nigeria, a military source said.