At least 40 people have been burned to death after a petrol pipeline exploded in Nigeria's commercial capital, Lagos, officials say.
Criminal gangs have been blamed for breaching the pipeline
Local people had been trying to collect fuel from the pipeline, which had been deliberately breached, when something caused the petrol to ignite.
Most of the victims were women and children, who had arrived with fuel containers, witnesses said.
The remains of many of the victims have been buried in mass graves.
"We gathered that about 45 or 50 people were involved - they were burned down. When we got to the site we found out that they had been buried... there are three mass graves of 40 dead already," Philip Daferiogho, a spokesman for the Nigerian Red Cross said.
The BBC's Alex Last in Lagos says the fireball scorched an area roughly the size of a football pitch.
Red Cross officials say they are now focusing their efforts on finding and treating injured people who have gone into hiding, scared of being arrested.
Such disasters are not unusual in oil-rich Nigeria.
A year ago, at least 260 people died in one pipeline explosion in Lagos.
Nigeria produces huge amounts of fuel from its vast oil reserves, but it remains out of legal reach to most of the poverty-stricken population.