The Alaafin of Oyo, Lamidi Adeyemi, on Sunday, warned that the Yoruba people could resort to self-help against the "increasing and incessant menace of herders" in the face of "apparent helplessness" of Nigeria's security agencies.
The Alaafin issued the warning in a letter - titled "Yoruba Question in Nigeria Conundrum" - directed at President Muhammadu Buhari, according to Daily Trust. He expressed worry about the country's insecurity.
"I am worried about the security situation in the country, especially in the South-west geo-political zone, nay the entire Yoruba-speaking area of the country including Kwara, Kogi and Edo states," said the monarch. "This has to do with the incessant and increasing menace of Fulani herdsmen that have laid siege in almost all the highways of Yoruba land."
Mr Buhari rode on the promise to ensure national security - apart from fighting corruption and reviving the economy - to be elected president.
But Nigeria's security problem appears to be worsening, with the South-west recording a growing spate of violence, especially kidnapping.
Apart from the North-east ravaged by the Boko Haram, the violence in the North-west has risen beyond the police constabulary role.
The oil-rich Niger Delta still remains volatile and the farmer-herdsmen conflict that mostly affects the North-central, especially during dry seasons, remains a challenge.
The Alaafin's intervention came amid heightened tension following the killing of Funke Olakunrin, a daughter of Yoruba leader Reuben Fasoranti. Mr Fasoranti's group, Afenifere, blamed Fulani herdsmen, but the police are yet to identify any suspect.
Armed herders, for several years, have been blamed for violence in parts of Yorubaland, but the killing of Mr Fasoranti's daughter marked the first high profile case which they would be accused of.
"Whether in Owo, Akure, Ilesa/Ife-Ibadan road or Ibarapa zone and Ijebu area of Ogun state, the story is the same," the Alaafin continued blaming the Fulani for insecurity in the South-west region. "I have held series of consultations with opinion moulders and eminent Yoruba leaders across board about the menace of these cattle herders with such assault like raping of our women and in some occasions, in the presence of their husbands.
"That is apart from massive destruction of our agricultural lands; which ultimately points to imminent starvation."
The Fulani contributed to the collapse of Old Oyo Empire. They established an emirate in Ilorin, originally a Yoruba town, and made attempt to penetrate further before being stopped in Osogbo, present-day Osun State - a historical context that explains the distrust and tension between the Yoruba and the Fulani group.
"On top of it all is the menace of professional kidnappers usually in military uniforms. What is more worrisome about the kidnapping notoriety is what looks like impunity which these kidnappers enjoy their nefarious activities.
"Worse still is the confidence with which they demand ransoms and collect such illegal levies at designated spots without any arm of security being able to lay siege on them as it was the practice in the recent past.
"Now, we cannot even talk of parading suspects, when in actual sense, no major arrests have been made in this part of the country. Without arrests, we cannot talk of their facing of the law.
"Unfortunately, and painfully indeed, in the face of the apparent helplessness of our security agencies, where do we go from here? "It is at the wake of this manifest frustration of our people that our people have found it unavoidable, even though reluctantly to resort to alternative measures to safeguard their lives and property.
"Suffice to say that in most part of Yoruba land, their pre-colonial military structures have not been totally collapsed. Hence, such structures like Odua People's Congress, Agbekoya and other vigilante," the Oyo monarch wrote.
The OPC, an armed Yoruba militia involved in vigilante work in parts of the Southwest, recently told the authorities it would 'respond appropriately' after the killing of Mr Fasoranti's daughter.