Nigerian police on Saturday said many people were feared dead after a petrol tanker veered off the road, caught fire and exploded as people tried to recover fuel.
The vehicle crashed in the Odukpani area of the southeastern state of Cross River, just north of the state capital, Calabar, at about 5pm (1600 GMT) on Friday.
Local residents rushed to collect the leaking fuel when it caught fire, triggering the blast.
Cross River state police spokeswoman Irene Ugbo said the blast could have been sparked by the clashing of steel containers used to scoop up the petrol.
"I can't confirm the exact number of casualties," she said, adding: "The casualties are high."
"I believe the casualty level could be more because people from other neighbouring communities had thronged the scene."