The graphic video circulating on social media caused an outcry and condemnation by groups including Amnesty International, and again raised concerns about alleged military abuses as Cameroon combats Boko Haram extremists in the north along the Nigerian border and Anglophone separatists in parts of the west.
President Paul Biya has ordered an investigation, government spokesman Issa Tchiroma Bakary said.
The video appears to show soldiers in a rural area blindfolding two women, who have small children strapped to their backs, and shooting them as other civilians watch. One of the uniformed men says in French that it is a heavy burden executing people but they don't have another option.
The government spokesman called the Central African nation's military professional and said the camouflage uniforms in the video were fabricated with the intention of destroying its reputation.
"The combat uniforms used by the Cameroonian army in such circumstances are standard combat suits, namely heavy helmets, bulletproof vests and rangers' boots. This is obviously not the case in the video," Bakary said. "The weapons displayed by the alleged soldiers presented in the video are not those used by the Cameroonian army in this area of operation."
Military spokesman Didier Badjeck also disavowed the video.
"It indicates how much our enemies are at work to distract the attention of the soldiers," Badjeck said. "Cameroon is signatory to international treaties and conventions and knows what it means to respect human dignity at war."
Amnesty International, however, said its own investigation has "gathered credible evidence that it was Cameroonian soldiers depicted in a video carrying out the horrific extrajudicial executions of two women and two young children." It was not clear when the video was made.
The human rights group said analysis of the weapons, dialogue and uniforms, along with witness testimonies, "all strongly suggest that the perpetrators of the executions are Cameroonian soldiers." The government's denial "simply doesn't stand up to scrutiny," it said.
"Given the gravity of these horrific acts - the cold-blooded and calculated slaughter of women and young children - these hasty and dismissive denials cast serious doubt over whether any investigation will be genuine," said Samira Daoud, deputy director of Amnesty International's West Africa office. "It is imperative that a proper, impartial investigation is undertaken and those responsible for these abhorrent acts are brought to justice."
Cameroon's security is a growing issue as the country faces elections in October. It is not yet clear whether Biya, who has been in power for 35 years, will run again.
Amnesty International in a report last year said the military brutally tortured Boko Haram suspects and held them incommunicado in illegal detention facilities. A separate Amnesty report this year accused both Cameroon's military and armed separatists fighting for the independence of English-speaking regions of using unnecessary and excessive force.
Associated Press writer Carley Petesch in Dakar, Senegal contributed.
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