Kano - At least 20 people were killed in violent clashes between Christian and Muslim mobs in Taraba state, prompting a round-the-clock curfew, an aid worker has told AFP.
"We have recovered 20 bodies from the violence so far," the source said, adding that the unrest had occurred in the town of Wukari, some 200 kilometres (125 miles) from the state capital Jalingo.
"We are still going round the town in search of more bodies," he said on condition of anonymity because he was not authorised to speak to the media about death tolls.
Local residents said Friday's violence erupted when the funeral procession of a traditional chief from the predominantly Christian Jukun ethnic group marched through a Muslim neighbourhood chanting slogans, which Muslims viewed as an act of provocation.
A Tabara state police spokesman and a spokesman for the state governor confirmed the unrest but declined to give a death toll.
"There was fighting between some Christian and Muslim mobs yesterday in Wukari during the funeral procession of a traditional ruler but the situation has been brought under control by security personnel and we are awaiting a comprehensive report on the situation," Joseph Kwaji, Taraba state police spokesman said.
"The state governor has imposed a 24-hour curfew on Wukari which is aimed at restoring normalcy in the town" after the fighting, said Kefas Sule, spokesman for the state governor.
Tensions have been on the rise in the mostly Christian town of Wukari since February, when a dispute over the use of a football pitch between Muslim and Christian soccer teams set off riots that claimed several lives.
The violence came a day after the state government inaugurated a committee to investigate the February violence.
It also follows a surge in violence and kidnappings in the restive north of Nigeria, the epicentre of an insurgency by Boko Haram Islamists, in recent months.
In late April fierce fighting between soldiers and Islamic fighters in the remote northeastern town of Baga left 187 dead, according to the Red Cross, in the deadliest episode since the insurgency began in 2009.
An area senator put the death toll from the attack at 228, but details remain murky about the clashes which also left nearly half the town destroyed after massive fires.
Human Rights Watch on Wednesday released satellite images showing massive destruction in Baga, voicing concern that the military has "tried to cover up" abuses that should be investigated by the International Criminal Court.
The military has pushed back aggressively against these reports and fiercely denied claims that soldiers fired on civilians or deliberately torched scores of homes.
The global rights watchdog said the insurgency in north and central Nigeria by Boko Haram has claimed 3,600 lives since 2009, including killings by the security forces.