A video uploaded to Facebook by one of US president Donald Trump's lawyers claims that 60 000 Christians have been killed by nomadic Muslim herdsmen in central Nigeria since 2001.The claim has been shared hundreds of thousands of times on Facebook but AFP has found no credible evidence to confirm the figure.What are we verifying? The video, uploaded by attorney Jay Sekulow on November 23, focuses on the long-running conflict over land and resources between ethnic Fulani Muslim cattle herders and largely Christian farmers.Central Nigeria is also called the Middle Belt and is where the country's mainly Muslim north meets the largely Christian south. It has been a flashpoint for violence for decades.The video originates from the Be Heard Project, an initiative of the American Center for Law and Justice, a conservative Christian lobby group based in Washington DC.Sekulow is listed as "chief counsel" at the organisation. He has also represented Trump on the investigation into alleged Russian interference in the 2016 US presidential election.The video claims the herders have killed 60 000 Christians since 2001, without citing a reference. AFP contacted the ACLJ to ask how it obtained the figure but it did not respond.Other organisations have published similar figures. Again, none has cited a relevant study or credible evidence.What do we know? The African Center for Strategic Studies has said 60 000 people have died in the conflict but combines two different statistics of total deaths in the region over separate time periods.It references a Nigerian government study reported by the BBC of 53 787 deaths in Plateau state between 2001-2004. But the government study is not related to the farmer-herder conflict. It also quotes an article in the Daily Beast, which credited a HuffPost report, that 6 500 people died in the farmer-herder conflict since 2010.But the story links to an unnamed expert without evidence to support it.The International Crisis Group has said political and religious claims of a Fulani jihadist uprising are conspiracies which have grown in response to the conflict, which is primarily about access to land and water.There are no reliable estimates for the total number of deaths since 2001 and no known estimates which divide the deaths along religious lines.The ICG has reported that some 12 000 people were killed between 2011 and 2016, and that in the first six months of 2018, 1 300 people lost their lives.Nigeria is facing violence across the country and in some northern states there are clashes between Muslim farmers and Muslim herders, indicating the underlying cause is not religion.The Global Terrorism Index 2018 acknowledges there was a "dramatic increase in violence involving Fulani extremists" in the last 12 months.It said nearly 1 700 violent deaths were attributed to "Fulani Ethnic Militia" between January and September this year. It said there had been 2,998 deaths attributed to Fulani since 2010.A December 2013 Human Rights Watch report estimated that more than 10 000 people in Plateau and neighbouring Kaduna state had been killed in communal violence since 1992.Yet the claim of Muslims targeting Christians has been spread, particularly in the United States, by groups such as Open Doors USA, which says it supports persecuted Christians, and the right-wing think-tank the Gatestone Institute.What conclusion can we draw? There is no credible evidence to support the claim that Muslims have killed 60 000 Christians in central Nigeria since 2001.There is no reliable death toll that identifies the religion of victims of the conflict and reports citing figures appear to have conflated wider studies about violence in the region.Attempts to catalogue the scale of the conflict - by whatever methodology - have given a lower death toll.Right-wing, conservative groups in the United States, however, have latched on to the narrative to further their agenda.