An oil spill from a crashed truck burst into flames in Kenya, killing at least 50 people who had crowded round in search of free fuel.
Rescuers said someone may have accidentally dropped a cigarette, although there was also a suspicion someone angered at being blocked by police may have started the fire on purpose.
"I have counted more than 50 bodies next to the overturned truck," Rift Valley police provincial commissioner Hassan Noor Hassan told Reuters from the scene. Another 82 people were critically injured, he said.
After the truck careered off the road near the central town of Molo, motorbike riders and others descended on the vehicle in the hope of scooping up petrol, witnesses said.
Then the spill caught fire around dusk, engulfing those closest.
"My two sons ran home, picked some jerrycans and ran to get some petrol. I tried to stop them but they did not listen, they told me everyone is going there for the free fuel," said one distraught woman, who would not give her name.
"Now I cannot trace them," she said, sobbing as she looked at the skull and bones of one corpse nearby.
Hundreds were still milling around the site on Saturday evening. Rescuers were helped by people with torches and car-lights.
Kenya Red Cross spokesman Titus Mung'ou also gave a death toll of more than 50.
"After the lorry overturned and it spilled a lot of petrol, hundreds of residents from the area, and motorcycle riders, came to try and get free fuel," he said. "Then it seems somebody lit a cigarette, causing the fire. Or someone who was stopped from getting close by the police started the fire on purpose."
The disaster in Molo followed the deaths of at least 25 people in Nairobi when a supermarket caught fire earlier this week.
Local media have been berating the government for poor safety standards and inadequate disaster preparedness.