An eye witness says 21 people have been found shot dead in the streets of Burundi's capital after the government said an unidentified group carried out coordinated attacks on three military installations elsewhere.

The witness on Saturday counted 21 bodies in the Nyakabiga neighborhood after Friday's violence, which is linked to President Pierre Nkurunziza's disputed third term in office. The person spoke on condition of anonymity due to safety concerns.

Nyakabiga was not among the neighborhoods where the military said attacks on its installations took place. Army spokesman Col. Gaspard Baratuza told state radio Friday three soldiers were killed in the pre-dawn raid by an unidentified group in Ngagara, Musaga and Mujejuru. He said the army later killed 12 of the attackers.