At least 19 people are dead after gunmen opened fire on a Catholic church in Nigeria's middle belt on Tuesday, police said.

Armed men stormed the building during early morning mass in a remote village in Benue state in what appears to be the latest in an ongoing conflict between Fulani cattle herders and farmers.

Two priests, Fr Joseph Gor and Felix Tyolaha, were among the dead, the local Catholic diocese of Makurdi said.

'The herdsmen burnt nearly 50 houses during the attack and sacked the entire community,' state police spokesman Terver Akase told CNN. 'We expect arrests to be made because they [the attackers] are becoming more brazen.'

The conflict between nomadic Fulani herders, who are mainly Muslim, and resident farmers, who are mainly Christian, has spiked in recent weeks.

Fulani herders are now more dangerous that Boko Haram for Nigeria's middle belt region, a report published earlier this month by the persecution charity International Christian Concern said.

In March there were 27 attacks by Fulani herdsmen, which led to the deaths of 225 Christians, thousands of families displaced from their homes and the prolific destruction of property. In contrast, Boko Haram killed 37 people in the same period, ICC said.

The group criticised the Nigerian government for a failure to keep the Fulani accountable. In a statement it said: 'This serious situation requires a serious response. Thus far in 2018, Fulani militants have killed more people than Boko Haram and affected a much larger area. Despite this, the federal government in Nigeria has paid little attention and allowed these militants to get away with mass murder.

'Even in areas where they have provided small amounts of security personnel, it has proven to be completely ineffective. We continue to call on the Nigerian government to reclaim the land that has been stolen by Fulani militants, rebuild the communities that have been destroyed, and protect Nigerian citizens from future attack.'