Cameroon's army, with backing from a regional anti-Boko Haram task force, have killed at least 100 fighters from the Nigerian armed group and freed 900 people it had held hostage, the army and defence ministry said on Wednesday.

"In the course of this operation, at least 100 members of Boko Haram were killed. Nine hundred hostages detained by Boko Haram were freed," army spokesman Colonel Didier Badjeck announced on Wednesday. 

Joseph Beti Assomo, Cameroon's minister of defence, said an "important stock of weapons and ammunition" and flags belonging to the Islamic State of Iraq and the Levant (ISIL), to which Boko Haram is affiliated, have been seized, according to the news site CameroonWeb. 


Related: Deadly suicide attack rocks northern Cameroon


He said multinational forces, including the Nigerian army as well as Benin and Chadian soldiers, were involved in the operation in the far north border area with Nigeria, from November 26 to 28. 

Because of restrictions to media and independent observers, the figures provided by the military cannot be independently verified.

But Al Jazeera's Ahmed Idris said: "Recently, countries in the region have been stepping up their fight against Boko Haram. And we've also seen how the group responded with more violence, attacking military and other soft targets." 

Aliyu Musa, an independent researcher of war and conflict studies and a Boko Haram specialist, said the reports were true, the number of deaths is "very significant".

"The Boko Haram fighters are not as organised as they used to be, and training those many fighters takes time," he said in an interview with Al Jazeera. 

Musa also said that it is important that Cameroon is coordinating the operation with its neighbouring countries, as it denies Boko Haram easy exit routes across the border. 

Suicide bombing threats

Musa added that the operation should have happened as early as July or August, when the deployment of a multinational force was first announced.

"This should have happened much earlier, because this terrorist group has been carrying out attacks in border regions," he said, pointing out that in recent weeks the group killed an ethnic ruler and his family in Niger.

Boko Haram conflict forcing people to flee homes in Lake Chad basin

By stepping up operations, he warned that Boko Haram could retaliate by carry out more suicide bombings.  

Last November, a suspected Boko Haram attack killed at least four civilians and wounded dozens near the Nigerian border. 

Boko Haram, which wants to implement Islamic law in Nigeria's northeast, has launched attacks in Nigeria and neighbouring countries including Cameroon over the past few months.

The armed group was using Cameroon's impoverished far north to stockpile supplies and recruits until the government cracked down last year.

Cameroon is part of an 8,700-strong regional force led by Nigeria against the group, expected to be operational by the end of the year.

Nigeria and Cameroon share a 1,690km border. 

Last October, the United States announced that up to 300 troops, as well as surveillance drones, have been deployed to Cameroon to fight Boko Haram.

Source: Al Jazeera and agencies