Cameroon’s government has said it will investigate a video, which according to a human rights group shows the “brutal killings” of at least a dozen unarmed people by the country’s security forces. A government spokesman said on Friday that authorities would open an probe, but added that the government was the victim of a “campaign of denigration” before a presidential election in October. The video, circulating on social media, shows multiple persons opening fire on a group of apparently unarmed people cowering against a wall. A man dressed in military fatigues then approaches and fires shots at close range. Amnesty International, a UK-based rights group, on Friday alleged that the “horrifying” video provides “credible evidence” that “Cameroon’s armed forces have committed grave crimes against civilians”. The group said in a statement that the video had been shot in the village of Achigaya in Cameroon’s Far North region.