LAGOS, Nigeria (AP) — Nigerian security forces are searching for armed gangs who killed 47 people in attacks in recent days in rural areas of the country's northwest, the latest killings in the troubled region.

The attacks took place in the northwest Kaduna state which neighbors Nigeria’s capital city, Abuja, Kaduna commissioner for security Samuel Aruwan confirmed.

No group has claimed responsibility for the attacks but they are suspected to be by the gangs of bandits who have killed at least 2,500 people in the northwest and central states so far in 2021, according to statistics collated by the U.S. Council on Foreign Relations. The attacks have escalated in the past three months so the death toll for the entire year is expected to increase.

The armed groups mostly consist of young men from the Fulani ethnic group who had traditionally worked as nomadic cattle herders and have become caught up in a decades-long conflict with Hausa farming communities over access to water and grazing land.

Security forces deployed after the attacks are patrolling the affected areas, but no arrests have been announced and details are still emerging. Local residents reported that the assailants rampaged for hours in some of the villages.

Nine people were killed across three villaged on Friday, according to Kaduna commissioner Aruwan, a reminder of how the armed groups are able to carry out prolonged assaults in remote locations where help is often delayed as a result of inadequate security presence.

Another 38 people were killed on Sunday by assailants in another part of Kaduna, Aruwan confirmed.

Houses, trucks, and cars were burned, along with agricultural produce at some farms, he said.

The ongoing violence in Nigeria’s troubled northwestern region has defied measures introduced by authorities including the deployment of thousands of security forces to restore peace in violent hotspots and the recent designation of the armed groups as terrorist organizations.

Part of the problem is that Nigeria's military is already overstretched in a decade-long war against Islamic extremist rebels in the northeast region. The rebels of Boko Haram and its offshoot, the Islamic State in West Africa Province are reported to have infiltrated the armed bandits of the northwest as they seek to expand their influence and control, according to local authorities.