Scores of bodies, many burned beyond recognition, were scattered around the ground near the blast site in the heavily populated Abule Egba neighborhood. Intense heat made it difficult for rescue workers to approach the scene, reported the Associated Press.
An armed gang punctured the underground pipeline overnight in order to siphon fuel into road tankers, according to Reuters.
Witnesses said hundreds of men, women and children collected leaking fuel in plastic buckets after the vandals broke into the pipeline shortly after midnight.
"This was a preventable tragedy," said Joel Ogundere, a lawyer who lives near the site, AP reported. "It was poverty, ignorance and greed."
Red Cross workers continued removing bodies throughout the day. The latest estimates had the death toll at more than 260.
"We can only recognize them through the skulls, the bodies are scattered over the ground," said Nigerian Red Cross official Ige Oladimeji, according to the AP.
In May, more than 150 people died in a similar explosion in Lagos.
Nigeria is Africa's largest oil producer, but corruption, poor management and limited refining facilities within the country often lead to fuel shortages for vehicles and cooking. In recent days, Nigerians had to wait in long lines at Lagos filling stations.
Industry experts estimate that about 5 percent of Nigerian crude oil is stolen for export by those with contacts in the military or government, Reuters reported.
When the pipelines are breached, the pooling gasoline sometimes catches fire, killing people nearby.
Fact Sheet: Copenhagen Climate Summit 