Amnesty International (AI) has said at least 1,813 people killed from January to date, across 17 states almost doubles the entire death toll of 2017.
Amnesty made this known in a statement on Wednesday, issued by its spokesman Isa Sanusi quoting the Nigeria Country Director, Osai Ojigho.
AI also blamed Nigerian authorities for failing to tame the killings, noting that the failure of security made attacks and reprisals frequent.
Ojigho said, "By failing to hold murderers to account, Nigerian authorities are encouraging impunity that is fueling rising insecurity across the country."
He explained that, "independently verified estimated figures indicate that since January 2018 at least 1813 people have been murdered in 17 states, which is double the 894 people killed in 2017."
"The death tolls reflect killings as a result of farmers-herders conflict, communal clashes, Boko Haram attacks and banditry," he added.
He said, "We are gravely concerned about the rising spate of killings across the country, especially the communal clashes between farmers and herders and attacks by bandits across at least 17 states."
"The authorities have a responsibility to protect lives and properties, but they are clearly not doing enough going by what is happening," said Osai Ojigho.
He added that, "The latest incidence in Plateau state, where armed gunmen attacked 11 villages on 23 June for at least seven hours and killed at least 200 villagers without intervention from security forces should be investigated."
He said, "That the violence in Plateau started after an attack, which was followed by reprisal attacks from Thursday 21 shows unacceptable security lapses."
Amnesty said despite the deployment of security forces, including the military in over 30 states, the escalation of these attacks shows that whatever is being done by authorities is not working.
Ojigho said, "We hope that President Buhari's commitment to bring those suspected to be criminally responsible for the killings in Plateau state to justice will break the impunity that has spread through the country."
"In addition, government must answer these questions: who are these attackers, where do they come from, where do they go after attacks, who arms them, why is security forces' response time very slow?" he added.
He said, "Amnesty International's investigations show worrying details of how frequently the security forces failed to protect villagers."
He said, "In all cases Amnesty International investigated, the attackers, usually arriving in their hundreds spend hours killing people and setting houses on fire and then disappeared without a trace."
Ojigho said Amnesty International is also very concerned about the impact of these killings on farming, especially with the affected villages and farmlands deserted because people fear going back to their homes.
He said, "We are at the peak of farming season, and communities affected by this wave of violence are largely agrarian. But because of fear of attacks they have either been displaced or unable to cultivate their farms, therefore their major source of food and income threatened by the attacks."
He said Amnesty International is calling on Nigerian authorities to address security lapses that make it easier for the killers to carry out attacks and disappear.