A former senior officer in Burundi's army says he and other army officers have formed a rebel movement known as the Republican Forces to remove President Pierre Nkurunziza from power.

Lt Col. Edouard Nshimirimana, who was in charge of military transmissions and communications before he defected in September, said Thursday that the main objective of the new rebel movement is to protect Burundians who are being killed because they are protesting against the violation of the country's constitution by Nkurunziza who extended his time in power.

Burundi has been rocked by turmoil since the ruling party announced in April that Nkurunziza would run for a third term in office. Nkurunziza won elections in July but the violence has since escalated.