Nigerian police say a pipeline explosion has killed as many as 200 people on the outskirts of Nigeria's largest city, Lagos. They believe oil thieves were tapping the pipeline when the blast happened.

Nigerian police said the explosion on Friday was an accident.

They said vandals had probably cut into the pipeline at llado, near Lagos, to steal oil, when a spark set off the explosion, which spread to 500 jerrycans full of oil nearby.

Police on the scene said at least 150 people were killed, many were incinerated immediately.

Lagos-based journalist Paul Okolo tells VOA that accidents of this nature are not unusual in Nigeria.

"People were scooping fuel from a leak," said Okolo.  "Whenever there is a burst pipe or they deliberately cut the pipe, people go and take fuel, either to resell or to use themselves. And that is when the accident happened."

Tapping into pipelines to steal oil is known as bunkering. It is estimated that it costs Nigeria 200,000 barrels of oil a day. With a mere spark sufficient to set the oil alight, bunkering frequently results in a lethal explosion.  Nigeria has suffered more than ten in the last seven years.

In a bid to diversify the economy along International Monetary Fund guidelines, Nigerian President Olusegun Obasanjo has cut fuel subsidies, leading to pump price hikes. The increases have been especially acute in recent weeks.

Journalist Okolo says many Nigerians are too poor to pay for these increases. He says many resort to bunkering.

"Poverty is a big issue in Nigeria," he added.  "A lot of people cannot afford to buy fuel. It now costs 65 Naira a liter, which is a bit less than 50 cents. That is a lot of money here. People will do anything to get it for less."

The blast came on the same day that three foreign oil workers were released in Nigeria's oil capital Port Harcourt after having been taken hostage for a day.  Militants in the oil-rich Niger Delta region say they are not benefiting from Nigeria's substantial oil trade.