Onitsha - The death toll from an ambush by gunmen in Nasarawa has reached 46, police said, with the state governor revealing that a local cult may be the culprits.
President Goodluck Jonathan cut short his trip to South Africa and Namibia to return home on Thursday and oversee efforts to contain threats to Nigerian security, highlighted by this week's bloodshed.
"Forty-six police officers were killed about 10 km (6 miles) from Lafia by members of a militia who had ambushed them on their way to an operation to arrest the leader of the militia group," police spokesman Sergie Ezegam said.
Local media quoted Nasarawa State Governor Tanko Al-Makura as saying the attack was carried out by a cult called Ombatse, meaning "the time has come" in the local Eggon language.
The group has attacked officials, churches and mosques in the past, he said, but added that this week's assault signified a marked escalation in the scale of its operations.
"Two weeks ago, we discovered a certain militia group holding arms and carrying out cult activities in the state," Al-Makura was quoted as saying in local papers.
"Since January, this thing has not abated and in the past two weeks, it has taken on a totally different dimension."
Two security sources also said they did not think the attack on Nassarawa was carried out by Boko Haram. The Ombatse group is motivated by ethnic rivalries within the state, one security source said.
Ansaru, dubbed a terrorist group by Britain, claimed responsibility for a January attack in Kogi state on a convoy of Nigerian soldiers en route to deployment with West African forces in Mali. Kogi is south of Abuja and borders Nassarawa.
Western governments are increasingly concerned about Nigerian militants linking up with other jihadist groups in West Africa.
Around 200 heavily armed suspected members of the group laid siege to the northeastern town of Bama on Tuesday, leaving 55 people dead, the military there said.
Attacks by Boko Haram have killed more than 3 000 people since 2009, based on figures from Human Rights Watch.