Nigeria's president has told security services to uncover the cause of a deadly blast at a pipeline near Lagos.
Security along the pipeline is being increased amid rescue efforts
More than 150 people died on Friday, many burnt beyond recognition, when petrol exploded while gushing from a suspected tapped pipeline.
A spokesman for President Olusegun Obasanjo said he had ordered a thorough police investigation and increased protection for other pipelines.
Some 2,000 people have died in similar incidents in Nigeria in recent years.
"President Obasanjo has received with great sadness and concern the news of the death of Nigerians in the explosion in Lagos," spokesman Oluremi Oyo told the AFP news agency.
"It is a grave reminder of similar incidents in the past. [Mr] Obasanjo said that people should never trifle for whatever reason with elements that can cause such catastrophe," she added.
Clean-up efforts continued on Saturday at the site of the explosion, on Atlas Creek Island on the outskirts of Lagos.
Many of the dead have been given a mass burial near the site of the blast, officials said.
The heat and severity of the blast left many victims unrecognisable.
But officially identifying the dead will be a difficult task, says the BBC's Alex Last in Lagos.
Many local people do not want to be connected to this incident, as relatives of those killed in similar accidents in the past have been prosecuted over the petrol theft.
So no relatives have come forward to claim the dead, and none of the injured have been found.
The Nigerian Red Cross says its workers are trawling the sea near the scene of the blast for any remaining corpses.
Sensing a potential contamination risk if the charred bodies are left untreated, health officials have decreed that victims should be buried at the earliest opportunity.
Visiting the scene of the blast on Saturday, Lagos health commissioner Tola Kasali blamed personal greed for the country's regular pipeline explosions.
"Because this thing has happened many times before, we thought it would be a deterrent, but apparently it wasn't enough deterrent for these people who died," he told the Associated Press.
"Anywhere you have a pipeline in this country, you have this problem because people are greedy and they want quick money."
Correspondents say the Friday morning blast incinerated all those within a 20m radius, but the exact number of casualties may not be known for some time.
The country's Red Cross said local people arrived on the scene after thieves had initially ruptured the pipeline.
"We found that vandals have drilled holes on [into] the pipeline, from where they have been stealing fuel," said Nigerian Red Cross Secretary General Abiodun Orebiyi.
NIGERIA PIPELINE DISASTERS
Dec 2004: At least 20 killed in Lagos
Sept 2004: At least 60 killed in Lagos
June 2003: At least 105 killed in Abia State
Jul 2000: At least 300 killed in Warri
Mar 2000: At least 50 killed in Abia State
Oct 1998: At least 1,000 killed in Jesse
Local people were apparently gathered around the site of the leak when the fuel ignited. Five hundred jerrycans were found at the scene.
Atlas Creek is a small fishing community but some people have moved there because rent is cheaper than Lagos, where they commute by speedboat.
The pipeline serves the Atlas Cove petrol depot, which supplies south-western Nigeria.
HAVE YOUR SAY
Everything boils down to poverty - I wonder why a country as rich as Nigeria is in this kind of predicament
Nlolu Omotosho, Houston, TX
Despite being the eighth-largest oil exporter in the world, Nigeria has to re-import refined oil products, such as petrol, because of decades of neglect of its own refineries. The pipelines often pass through poor communities, who break them to steal the precious fuel.
Militants have frequently targeted the centre of Nigeria's oil industry in the Niger Delta, further to the east.