Below is a visualization and description of some of the most significant incidents of political violence in Nigeria from September 11 to September 17, 2021. This update also represents violence related to Boko Haram in Cameroon, Chad, and Niger. These incidents are included in the Nigeria Security Tracker.
- September 11: Electoral violence resulted in one death during the by-election in Isoko South, Delta.
- September 11: Bandits killed twelve military officers in Maru, Zamfara.
- September 11: Gunmen killed one and kidnapped "many" (estimated at ten) in Takum, Taraba.
- September 12: Gunmen killed four soldiers and freed 240 inmates from a correctional center in Kabba/Bunu, Kogi.
- September 12: Police officers killed three Indigenous People of Biafra (IPOB) militants in Orlu, Imo.
- September 12: Herdsmen killed thirteen in Zangon Kataf, Kaduna.
- September 12: Communal violence resulted in two deaths in Oyi, Anambra.
- September 13: Kidnappers abducted four in Moba, Ekiti.
- September 13: Bandits killed one soldier and kidnapped nine civilians in Zaria, Kaduna.
- September 13: Kidnappers abducted the Edo Peoples Democratic Party (PDP) chieftain and his driver in Uhunmwonde, Edo.
- September 14: Gunmen killed a priest at his church in Orsu, Imo.
- September 14: Kidnappers abducted a Zamfara Emir and several others (estimated at ten total) and killed one police escort in Kaduna South, Kaduna.
- September 14: Bandits killed one and kidnapped five in Chikun, Kaduna.
- September 15: A Nigerian Air Force airstrike accidentally killed nine civilians in Yunusari, Yobe.
- September 15: Kidnappers killed one and abducted three in Kabba/Bunu, Kogi.
- September 15: Cult clashes led to four deaths in Gboko Local Government Area (LGA) and one death in Makurdi LGA in Benue.
- September 16: The Islamic State in West Africa (ISWA) killed sixteen soldiers and two civilians and took two soldiers hostage in Maiduguri, Borno.
- September 16: Communal violence resulted in three deaths in Ughelli North, Delta.
- September 16: Vigilantes killed eleven bandits in Kogi, Kogi.
- September 16: Bandits killed two in Giwa, Kaduna.
- September 16: Police officers killed two IPOB members in Onicha, Ebonyi.
- September 17: Bandits killed two and kidnapped four in Tangaza, Sokoto; residents then killed six of the attackers.