Huge Nigeria delta toll - Amnesty

Many believe the gunmen were recruited to intimidate rivals in last year's elections

Fighting in the southern Nigerian city of Port Harcourt has killed up to 500 people over the past month, says Amnesty International.

It says many more were injured and tens of thousands driven from their homes after clashes involving armed gangs.

Amnesty wrote to the state governor saying it was "deeply concerned" that troops had been given orders to use "maximum force" to quell the fighting.

Officials defended the decision saying they had to protect lives and property.

A spokesman for Rivers State Governor Peter Odili rejected the allegation that up to 500 had died, saying the authorities stuck by the police figure of about 20.

Gangs

Amnesty says the authorities are deliberately playing down the figures.

"Amnesty International's analysis, based on international and national media reports combined with statements from reliable sources, points to a figure of up to 500," the organisation said.

The present warlords were agents of the state government Sara Igbe Former state security official Fighting for Nigeria's oil

"Most of the victims were civilians, including an unconfirmed number of women and children, who had taken no part in the fighting and were killed or injured as a result of being targeted or indiscriminately shot at by members of the armed groups," it said.

Port Harcourt is the hub of Nigeria's oil industry and violence has raged in the surrounding area for the past two years.

The BBC's Sola Odunfa visited Port Harcourt recently and said that armed gunmen belong to two main gangs, who it is widely believed, were created, funded and armed by politicians during last year's election

They are said to have diverted from political violence and intimidation to stealing crude oil after last year's elections.