The slaughter continues.

(CNN) – At least 22 people have been killed in three separate attacks in northeastern Nigeria since Friday, including 15 Christians shot Sunday inside a church, according to officials.

The violence began early Friday when unidentified gunmen raided a village in Musari, in Borno state, killing five people, said Joint Task Force Lt. Col. Sagir Musa. JTF troops responded, and a gun battle ensued. Three of the attackers were killed, and troops recovered weapons and ammunition. Musa declined to provide further details of the attack.

Also Friday, gunmen with suspected ties to the Islamist militant group Boko Haram killed two people and wounded another in an attack in Maiha, in Adamawa state, according to Godfrey Okeke, Adamawa state commissioner. The attackers freed 35 inmates from the Maiha prison and set government buildings on fire, Okeke said.

In Sunday’s attack, gunmen entered a church in Chibok, also in Borno state, and killed at least 15 worshipers, said Mohammed Kana, a regional official for the National Emergency Management Agency.