Nigeria, Africa’s most populous nation, faces a myriad of security threats — from Islamic State-linked militants in the north to separatist movements in the south.

Much of the violence is related to religious extremism, but some attacks are fueled by conflicts over natural resources. What all have in common, though, is that civilians are most often the victims.

Armed groups are able to carry out prolonged assaults in remote locations where help is often delayed by an inadequate security presence. In many cases, accurate death tolls are never compiled.

A look at some of the attacks targeting Nigerian civilians in the past five years:

JUNE 5, 2022 — Gunmen attack a service at St. Francis Catholic Church in Owo, located in Ondo state in southwestern Nigeria. A local state legislator says at least 50 people were killed.

APRIL 2022 — An armed gang attacks four villages in a remote corner of Plateau state in northern Nigeria, killing more than 100 people.

MARCH 2022 — Gunmen attack a train near Nigeria’s capital with explosives and gunfire, killing at least seven people.

JANUARY 2022 — Dozens of civilians are killed in three days of bloodshed by armed groups in northwest Zamfara state.

DECEMBER 2021 — Gunmen open fire on a bus in Sokoto state in northwestern Nigeria, killing at least 23 passengers.

SEPTEMBER 2021 — An attack in a village in northern Kaduna state leaves at least 37 dead. Locals say the violence stemmed from an ongoing conflict between herders and farmers over land and water issues.

NOVEMBER 2020 — Suspected members of the Islamic militant group Boko Haram kill at least 40 farmers and fishermen in northeastern Borno state.

JUNE 2020 — Suspected members of the Islamic extremist group Boko Haram kill at least 81 people in a village in northeastern Borno state.

JULY 2019 — Suspected Boko Haram extremists kill more than 60 people in an attack on villagers leaving a funeral in northeastern Borno state.

JUNE 2019 — A suicide bomber kills at least 30 people gathered to watch a soccer match on television in northeastern Borno state.

APRIL 2019 — Suspected Boko Haram extremists attack a village in northeastern Borno state, killing at least 25 people who had returned home from a wedding.

FEBRUARY 2019 — Clashes between farmers and herdsmen leave 29 dead in central Kaduna state.

FEBRUARY 2019 — Suspected Boko Haram militants kill at least 60 people in a town near the Cameroonian border in northeastern Borno state.

JUNE 2018 — More than 200 people die in clashes between farmers and herders in central Plateau state.

JUNE 2018 — Clashes between herders and farmers in central Plateau state leave 86 dead.

MAY 2018 — At least 24 people are killed in an attack on a mosque in northern Adamawa state.

APRIL 2018 — Gunmen kill 15 people in an attack on a Catholic church, including two priests in central Benue state.

FEBRUARY 2018 — Three suicide bombers attack a crowded market in northern Borno state, killing at least 20 people.

JANUARY 2018 — Gunmen fatally shoot at least 17 worshippers at a church service for the new year in Rivers state.

NOVEMBER 2017 — At least 50 people are killed in a suicide bombing at a mosque during morning prayers in northeastern Adamawa state.

AUGUST 2017 — Suspected Boko Haram extremists attacked a camp for displaced people and a nearby market in northeastern Borno state, killing at least 20.