WARRI, NIGERIA — At least 500 people have died in an inferno which engulfed hundreds of people scavenging for petrol from a burst pipeline in southern Nigeria, witnesses said Monday.

"The casualty is bigger than initially thought and more are still dying. At least 500 people are so far dead," said Joy Aigbe, a nurse in the oil town of Warri where many of the victims of the disaster Sunday at Apawor village were taken.

"The crowd at the pipeline were bathed in petrol and it took just a spark ... to set them ablaze."

She said many of the dead were women and children who had thronged the area with cans and buckets to collect spilled petrol from a burst pipeline belonging to the state-owned Pipeline and Products Marketing Company (PPMC).

"The people who crowded at the pipeline had bathed themselves in petrol and it took just a spark from the exhaust of a motor bike to set them ablaze," said Dafe Emutoru, a local government official who was one of the first on the scene of Sunday's fireball.

A journalist who visited hospitals around the oil town of Warri said: "The death toll is rising by the minute, at least five people are dying every hour."

No official death toll has so far been announced for the disaster.

One pathetic sight was a woman with her baby tied to her back, both burnt to death.

Officials of PPMC, which fed petrol from the refinery in Warri through the pipeline to the northern city of Kaduna, have blamed the disaster on sabotage.

Many of the dead were said to have been trapped in a ditch where a pool of petrol had collected. A wide patch of land the size of a soccer pitch was charred as the fire trailed the flow of the volatile liquid.

Latest reports said the disaster scene was still littered with unidentified bodies burnt beyond recognition, while plumes of thick black smoke still rose from the persisting fire being battled by firefighters.

"One pathetic sight was that of a woman with her baby still tied to her back, both of them burnt to death," said a witness at the scene Monday. "In many cases only the skeletons of the victims are left."

PPMC officials said the blaze was coming under control.

"We have shut off the pipeline and it's just for the spilled fuel to burn out," one official said.

"It was an act of sabotage," Emmanuel Akhihiero, maintenance superintendent of PPMC told Navy Commander Walter Feghabor, military governor of Delta State who visited the scene.

Reports of sabotage have been growing since oil-producing Nigeria fell into the grip of frequent fuel shortages with the failure of its poorly maintained refineries to meet demand.

But the latest incident is part of a recent pattern of unrest in Nigeria's oil region where impoverished local communities have grown restive over their perceived neglect by government and oil multinationals.

This month ethnic Ijaw youths have stopped the flow of one-third of Nigeria's oil exports of over two million barrels per day (bpd) to back demands for a greater political say for the country's fourth-largest ethnic group and more amenities for their communities.

The situation is further complicated by ethnic rivalries which erupted in Warri in rioting Friday with three people dead. Further skirmishes were reported Sunday between Ijaws and their Itshekiri rivals, but no deaths were reported.

Apart from threatening the source of over 90 percent of the export income of Africa's most populous country of 104 million, the crisis in the oil region also raises worries about military ruler General Abdulsalami Abubakar's promise to restore civilian rule next May.

"I feel terribly bad. I can't believe what I have seen," Feghabor told reporters at the scene of the fire Sunday. He directed that unidentified bodies be given a mass burial.

AFTERWORD:

Two days later the death toll passed 700 — and continued to climb — as more of the 2,000 victims succumbed to their burns. More than 300 unidentifiable dead were buried near the disaster site.

The United Nations Children's Fund (UNICEF), the Red Cross and the World Health Organization (WHO) have dispatched emergency medical teams to help the overwhelmed hospitals around Warri.

Military ruler General Abdulsalami Abubakar, who had promised during a visit to the scene of the disaster to pay the medical bills of the survivors, announced the opening of an investigation by the state oil firm.