Gunmen killed 24 villagers in a remote part of north-central Nigeria, authorities said on Sunday, raising further concerns about the West African nation’s ongoing security challenges.

The gunmen arrived at the Akpuuna village in Benue state’s Ukum district on Saturday, shooting dead the villagers before escaping the area, according to Tersoo Kula, the spokesman for Benue state’s governor.

Police blamed the attack on a “militia gang,” a common reference to armed groups in Nigeria’s hard-hit northwest and central regions where armed violence has claimed the lives of thousands in the last year.

Catherine Anene, police spokeswoman in Benue, said eight bodies were retrieved from the scene. Local officials, including legislator Ezra Nyiyongo, said there were at least 24 killed and several others injured.

“I lack words to express my shock and sympathy to the families of the lost ones,” said Nyiyongo as he published the names of those killed.

Benue Gov. Hyacinth Iormem Alia said the attack was unprovoked and directed security agents to hunt for the suspects, his spokesman Kula said.

“Government will do everything possible to put measures in place to checkmate these things and forestall a re-occurrence,” Kalu said.

Such attacks are common in many parts of Nigeria’s northern region where local herdsmen have clashed in the past with farmers over limited access to land and water. More than 100 people have been killed this year in the violence in Benue alone. Arrests are rare after the killings.

The gunmen in the latest incident operated for more than two hours without the intervention of security forces, according to Emmanuel Udende, who represents the village at the Nigerian Senate. His comment re-echoed concerns about the security of villagers in many violent hotspots where the Nigerian security forces are far outnumbered and outgunned.