At least seven suspected kidnappers were set ablaze and killed in a "barbaric" mob attack in Nigeria's southern town of Uromi, in Edo state, the governor said on Friday.

Edo Governor Monday Okpebholo condemned the mob killing of the individuals, pledging that those responsible would be prosecuted to the fullest extent of the law.

Preliminary investigations revealed that the victims, identified as northern Hausa hunters, were stopped by local security while travelling in a commercial truck.

A search of the vehicle uncovered guns, triggering a mob attack by residents who accused them of being kidnappers and Fulani herdsmen.

"The commissioner of police has been directed to launch a full-scale investigation into the matter," Okpebholo said in a statement, adding that at least four people have been arrested for their involvement in the attack.

Kidnapping for ransom and violence attributed to Fulani herders have become a pervasive and escalating crisis in Nigeria, fuelling insecurity, displacement, and inter-ethnic tensions across the country.

Hundreds have been killed in recent years in clashes pitting the semi-nomadic, cattle-herding Fulani people against more settled farming communities in Nigeria.