The oil pipeline was ruptured by thieves and exploded on Thursday at Onicha Amiyi-Uhu in the southeastern Abia state, sparking Nigeria's worst oil-related disaster since 2000.

The explosion left many of the bodies burnt beyond recognition leaving local officials no choice but to bury them in mass graves in order to prevent the outbreak of disease.

Locals are reported to have accused the company for not repairing the vandalised pipeline that they say gushed fuel for weeks before exploding.

The 10-year-old pipeline pumps kerosene, diesel and gasoline from a refinery in Port Harcourt to the southeastern city of Enugu. Vandals frequently puncture the pipe and young men collect the gushing fuel in jerry-cans and barrels and resell it -a practice known as "scooping" or "bunkering."

The company maintains that the first they heard of the leak was after the explosion and that it was impossible to keep an eye on all 5,000 km of its pipelines.

Oil pipeline fires accidentally started by fuel thieves have killed hundreds of villagers in the past four years in Nigeria, the world's eighth biggest crude oil exporter.

About 200 people were killed in November 2000 when a petrol tanker crashed into a queue of vehicles at an illegal checkpoint in southwest town of Ile-Ife.