Cameroon's army says it has killed 86 Boko Haram militants and detained 1,000 people suspected of links to the Islamist group, as central African leaders held talks on how to combat its bloody insurgency.

Five Cameroonian soldiers were also killed during the clashes in the Waza region near the border with Nigeria, defence ministry spokesman Didier Badjeck said Monday.

Nigeria-based Boko Haram has widened its attacks into neighbouring nations, notably Cameroon and Chad, in a conflict estimated to have claimed a total 13,000 lives since 2009.

Representatives of 10 nations, meeting in the Cameroonian capital Yaounde on Monday under the aegis of the Economic Community of Central African States (ECCAS), urged the international community to provide more support in the fightback against the Islamists.

"We have to eradicate Boko Haram," said Cameroon's President Paul Biya, as attendees pledged to create a 76-million-euro ($86-million) fund to fight the group.

Biya declared that Boko Haram's utter disregard for human dignity meant "a total impossibility of compromise", but added that the fight against terrorism was not a "crusade against Islam".

Nigeria, where elections have been postponed by six weeks until late March because of Boko Haram activity in swathes of the northeast, was absent from the talks as it is not an ECCAS member.

The aim of Monday's discussion was to come up with "an agreed solution" on the fight against the extremists, a source close to the Cameroonian government told AFP.

Chad, Cameroon, Niger and Nigeria have formed a military alliance to combat the notoriously brutal militants, who are fighting to create a hardline Islamic state.

A Cameroonian army official announced that more than 1,000 people suspected of being affiliated with Boko Haram were being held in the town of Maroua, in the country's Far North region, where more than 2,000 Cameroonian soldiers have been deployed since August last year.

"At the moment, the prison of Maroua is holding more than 1,000 Boko Haram (suspects)," said Colonel Joseph Nouma, commander of a local operation to combat the Islamist militants.

The detentions came as police in Niger said they had arrested more than 160 people suspected of having links to Boko Haram in the country's Diffa region, a border area with Nigeria which was attacked by the Islamist group this month.

- 'Solidarity' –

Nigeria, which has been most affected by Boko Haram violence, meanwhile announced its troops had recaptured the strategic garrison town of Monguno in the northeast, which had fallen into Boko Haram hands late last month.

"Troops in a military operation spearheaded by highly coordinated air assaults have completed the mission of clearing terrorists from Monguno and environs this morning," defence spokesman Chris Olukolade said.

With his country's troops actively engaged in combatting Boko Haram, ECCAS chairman Deby called on nations in the economic group "who have not yet been struck" by the insurgency "to show their solidarity".

"We also call on the international community to provide its support -- in equipment, diplomacy, finance, logistics and humanitarian aid -- to the efforts made by ECCAS," Deby said.

After previous talks in Yaounde, Nigeria's immediate neighbours, Cameroon, Chad, Niger and Benin announced on February 7 that they would mobilise a regional force of 8,700 men to fight Boko Haram.

Operational plans for the regional force have yet to be submitted to the Peace and Security Council of the African Union for approval before being sent to the United Nations Security Council, according to a statement released after the regional talks.

In a statement read in Yaounde on his behalf, UN Secretary General Ban Ki-moon warned that "a purely military solution" would not suffice to deal with Boko Haram.

The fight called for a "multidimensional approach... that will meet the challenges of stabilisation in the long term," the UN chief said, referring to the region's economic and social challenges.