A new outbreak of ethnic violence has left at least four villagers dead and threatened peace talks in Nigeria's oil-rich Niger Delta, local leaders said yesterday.

The renewed fighting could delay moves by US and European oil giants to restart production at their abandoned facilities in the troubled swamp region west of the oil city of Warri.

Warri's police commander, Joseph Abiona, said that armed militants from the Ijaw ethnic group on Thursday attacked a village belonging to the neighbouring Itsekiri community.

"The Ijaws attacked Itsekiris of the riverine area because of a previous attack on their community.

Last week pirates believed to be Itsekiris ambushed and killed some Ijaws," he said.

Itsekiri youth leader Eric Igban said that his men had been to the village, Abi-Gborodo, early Friday to inspect the damage and found it to have been almost completely burned down.

"There were at least four bodies lying on the ground. There may have been more dead if people with bullet wounds ran into the bush and died later, we don't know," he said.

In March fighting between the two ethnic groups - and clashes with security forces -left a dozen villages abandoned and sent thousands of refugees fleeing the delta swamps.

Dozens were killed and three oil majors - Anglo-Dutch giant Shell, US-based ChevronTexaco and France's Total - evacuated their facilities and stopped production in the area.

Nigeria is the world's fifth largest exporter of crude oil, with an Opec quota of just over two million barrels per day.

At the height of the trouble more than 40% of Nigeria's production was halted, forcing up world oil prices.

Some production has now restarted and the governor of Delta State, James Ibori, has relocated the seat of his government to Warri to take personal charge of peace talks.

But Igban warned that that peace process was now in jeopardy.

"The governor asked us to come to the negotiating table, to remain peaceful for the sake of development, but with this all that could crumble," he said.

He also denied that Itsekiris had been behind last week's attack on Ijaws, said to have taken at a river junction in the Burutu area southwest of Warri.

He said internal Ijaw feuding had been behind the casualties.

This charge was angrily rejected by the Ijaw. Oboko Bello, president of the hardline Federation Niger Delta Ijaw Communities (FNDIC), described the earlier attack as an "act of war".

"Boats with uniformed men came from the Itsekiri area and attacked our people. 15 were murdered in cold blood.

We think the army are working with the Itsekiris," he said.

He denied that any organised Ijaw group had mounted Thursday's apparent reprisal attack, but admitted: "The relatives of the deceased could have been aggrieved and done this".

Last week an AFP reporter travelled by boat with Ibori and a Shell manager to inspect damage to the villages and oil facilities in the flashpoint area.

At least one Itsekiri village, Otumara, had been razed to the ground and the nearby Shell pumping station damaged and ransacked, but Ijaw leaders assured their visitors that the trouble was over.

Shell officials said then that another flow-station, at Jones Creek, appeared largely untouched, and that the firm might soon begin to resume production of 130 000 barrels a day.

Abi-Gborodo, the scene of the latest attack, is in the Olero oil field operated by ChevronTexaco but which the firm said had been lying dormant since the March hostilities.

"This is to ensure the safety of our staff and facilities. We will go back when we adjudge the situation to be normal," ChevronTexaco spokesperson Tunde Ilevbare said. – Sapa-AFP.