Rights group, Amnesty International, says the failure of Nigerian government to hold murderers to account is encouraging them and fueling rising insecurity across the country.
The group made the observation on Thursday through a statement signed by its media officer, Isa Sanusi.
It said independently verified estimated figures showed at least 1813 people have been murdered in 17 states in the country this year, double the 894 people killed in 2017.
According to the group, the death tolls reflect killings as a result of farmers-herders conflict, communal clashes, Boko Haram attacks and banditry.
"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 statement quoted Osai Ojigho, Director Amnesty International Nigeria
"The authorities have a responsibility to protect lives and properties, but they are clearly not doing enough going by what is happening," Mr Ojigho said.
"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."
It said it shows unacceptable security lapses that the violence in Plateau started after an attack, which was followed by reprisal attacks from Thursday to Saturday last week.
"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.
"There is urgent need for people who are suspected of committing crimes to be held accountable.
"We hope that President (Muhammadu) 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?"
Amnesty International said it is currently investigating the rising insecurity that has resulted in the increase in killings across Nigeria.
It said its investigations showed "worrying details of how frequently the security forces failed to protect villagers. 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.
Impact on food security:
The group also expressed concern about the impact of the killings on farming, "especially with the affected villages and farmlands deserted because people fear going back to their homes.
"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," Mr Ojigho said.
The organisation called on government to address "security lapses that make it easier for the killers to carry out attacks and disappear.
"Making arrests and bringing to justice those suspected to be responsible for these attacks is crucial in ending the killings that are gradually turning into almost a daily occurrence. In many instances these killings happen and no arrests take place," Mr Ojigho said.