UN chief Ban Ki-moon appealed yesterday for "maximum restraint" amid revulsion at the slaughter of more than 500 Christians in Nigeria, as survivors told how the killers chopped down their victims.

The Vatican led a wave of outrage with spokesman Federico Lombardi expressing the Catholic Church's "sadness" at the "horrible acts of violence".

Mr Ban told reporters he was "deeply concerned".

"I appeal to all concerned to exercise maximum restraint," he said.

Funerals began taking place for victims of the three-hour orgy of violence on Sunday in three Christian villages close to the northern city of Jos, blamed on members of the mainly Muslim Fulani ethnic group.

While troops were deployed to the villages to prevent new attacks, security forces detained 95 suspects but faced bitter criticism over how the killers were able to go on the rampage at a time when a curfew was meant to be in force.

Newspapers reported that Muslim residents of the villages in Plateau state had been warned by phone text message, two days prior to the attack, so they could make good their escape before the exit points were sealed off.

Survivors said the attackers were able to separate the Fulanis from members of the rival Berom group by chanting "nagge", the Fulani word for cattle. Those who failed to respond in the same language were hacked to death.

One local paper said the gangs shouted "Allah Akhbar" before breaking into homes and setting them alight in the early hours of Sunday. Churches were among the buildings that were burned down.

The information ministry said pregnant women were among those killed and around 200 people were being treated in hospital.

"We have over 500 killed in three villages and the survivors are busy burying their dead," said State Information Commissioner Gregory Yenlong.