A mother comforts her crying child in Dogo Nahwa, Nigeria, on Monday after hundreds of people were reportedly slaughtered on Sunday, according to residents, aid groups and journalists. (Jon Gambrell/Associated Press)Nigerian officials say close to 500 people may have been killed in weekend sectarian violence near the central city of Jos, not the 200 first reported.

Witnesses said gangs armed with guns and machetes rampaged through three mostly Christian villages, firing shots to draw people from their homes and then running them down and killing them.

Yemi Kosoko, a reporter with the independent Nigerian news network Channels, told The Associated Press most of the bodies appeared to be women and children killed by blows from machetes.

Plateau state spokesman Gregory Yenlong told the New York Times the number of dead was about 500, while Shehu Sani, president of the Civil Rights Congress, told the Bloomberg new agency that 492 people died.

One aid worker said Monday it was difficult to tell how many people had been killed because some bodies were charred beyond recognition.

Nigeria, Africa's most populous country with an estimated population of close to 150 million, has had a long history of both ethnic and religious violence.

A victim lies in hospital after surviving interfaith violence in the town of Dogo Nahawa, Nigeria, about five kilometres south of the city of Jos, on Sunday. (NTA TV/Associated Press)

The attack occurred in a middle belt between the predominately Muslim north and the Christian south, where sectarian violence has been recurring. More than 300 residents died during a similar uprising in 2008.

The attack was an apparent reprisal for similar attacks on Muslims in January.

A strict curfew has been in place since the January violence. It is unclear how the attackers managed to elude the military curfew early Sunday.

Acting president Goodluck Jonathan said additional security forces would be stationed along the central Nigerian state's borders to keep outsiders from bringing more fighters and weapons to the region.

"[We will] undertake strategic initiatives to confront and defeat these roving bands of killers," he said in a statement.

"While it is too early to state categorically what is responsible for this renewed wave of violence, we want to inform Nigerians that the security services are on top of the situation."

With files from The Associated Press