Armed men killed at least six civilians and five soldiers in an attack in Nigeria's southeastern Abia state, the military said Friday, prompting the state government to offer a $16,850 reward for information on the gunmen.
The attack on Thursday was the latest in a string of raids in a region rife with separatist violence.
The assailants killed five soldiers deployed as peacekeepers in the area, and the six civilians who died were caught in the crossfire, defense spokesperson Major-General Edward Buba said.
No group claimed responsibility, but the army blamed the outlawed separatist Indigenous People of Biafra (IPOB) movement, which wants the surrounding region to secede from Nigeria.
The attack was at a military checkpoint at Obikabia junction in Obingwa local government area, Buba said in a statement.
"The military will be fierce in its response. We will bring overwhelming military pressure on the group to ensure their total defeat," he said.
Abia information commissioner Prince Okey Kanu urged the military to show restraint in their response.
The military has previously been accused by rights groups of using excessive force and targeting innocent civilians when responding to similar attacks, charges it denies.
The unrest in the southeast has put pressure on a government and military already struggling to contain attacks and kidnappings in the northwest, a 15-year-old Islamist insurgency in the northeast, and sectarian and herder-farmer clashes in central regions.
IPOB campaigns for the secession of southeastern Nigeria, where the majority belong to the Igbo group.
The movement's leader — Nnamdi Kanu, a British citizen arrested in Kenya in 2021 — is now on trial in Nigeria on terrorism charges.
More than a million people died, mostly from starvation, during a three-year civil war in the late 1960s when the region attempted to secede under the name of the Republic of Biafra.