President Muhammadu Buhari has ordered the security forces to crack down on cattle raiders accused of killing hundreds of people this year.
Soldiers and police would “go after the groups terrorising innocent people all over the country”, he said.
The raids are seen as the biggest security threat facing Nigeria after the Islamist-led insurgency.
Nomadic herders from the Fulani ethnic group and farming communities often clash for control of land and water.
The announcement comes after national outrage over the killing of at least 20 people on Monday in a raid on Monday on the Ukpabi Nimbo community in south-eastern Enugu State.
In a statement, Mr Buhari said he deeply sympathised with those who had lost their lives.
He had ordered Nigeria’s army and police chiefs to “secure all communities under attack by herdsmen”, Mr Buhari added.
“This government will not allow these attacks to continue,” the president said.
In February, about 300 people were killed and tens of thousands left homeless in a tit-for-tat raid in central Benue state, local media reported.
Homes, food barns and churches were also destroyed, reports said.
More than 1, 200 people were killed in 2014 by different Fulani groups, according to the Global Terrorism Index.