A pipeline in south western Nigeria has caught fire and exploded in an incident believed to be caused by thieves seeking to steal petrol, but the number of casualties was unclear, officials said Saturday. The fire began late Friday on a pipeline operated by state oil firm NNPC which transports petrol in Ogun state, said Ibrahim Farinloye of the National Emergency Management Agency. Authorities have since shut down the pipeline, but rescuers have not yet been able to access the site to determine if there were casualties, he said. “NEMA and NNPC wish to confirm that there was an explosion from the pipeline in the area,” Farinloye said. “When the report reached us, we immediately shut down the flow to suffocate supplies to the fire to enable us to put out the fire easily.”