The herdsmen had invaded a Catholic church in Benue and killed two priests and 17 other worshippers.
Gun-wielding herdsmen had in the early hours of Tuesday, April 24, attacked St. Ignatius Quasi Parish Ukpor-Mbalom in Ayar-Mbalom community of Gwer East Local Government Area of Benue State.
They reportedly killed two Catholic priests and 17 other worshipers.
The attackers were also said to have burnt down over 100 houses during the onslaught.
Reacting to the incident on Twitter, President Buhari assured that the perpetrators of the "heinous killings" will be brought to book.
"I extend my sincere condolences to the Govt and people of Benue State, the Mbalom community, and especially the Bishop, priests & members of the St Ignatius' Catholic Church, whose premises was the unfortunate venue of the heinous killings of worshippers & two priests by gunmen", the President tweeted on Tuesday night.
In January 2018, Benue State Governor Samuel Ortom buried 73 of his citizens who had been killed by armed herdsmen, in one day.
The herders are opposed to the anti-grazing law in Benue and have vowed to continue the attacks until the law is reversed.
Ortom, however, had repeatedly asserted that there is no going back on the anti-grazing law.
This latest herdsmen attack on a church in Benue is coming just days after at least 32 Tiv villagers were reportedly killed by suspected herdsmen who carried out coordinated attacks on several communities across Nasarawa state between Saturday, April 14 and Monday, April 16, 2018.