A mysterious white foamy substance that suddenly appeared along one of Nigeria's busiest highways has prompted an urgent environmental investigation, with authorities warning the public to stay away until tests reveal what it is.
The unusual sight on the Kaduna-Abuja Expressway has drawn large crowds of curious motorists, fuelled widespread speculation and raised concerns over possible health and environmental risks.
The National Environmental Standards and Regulations Enforcement Agency (Nesrea) has advised members of the public not to touch the unidentified substance or go near the affected area as investigations continue. The foam was spotted along the Kaduna-Abuja Expressway, a key road linking northern Nigeria to the country's federal capital.
Since the substance appeared a few days ago, hundreds of motorists have stopped along the highway to take photographs, with many also sharing images and videos on social media. While some suggested it could have been caused by a chemical spill, others were simply fascinated by the unusual scene.
One of the motorists who regularly uses the highway, Isah Aminu, said he first heard about the incident from another driver, who claimed that "clouds had fallen from the sky".
"That was the first information many of us got - that it's clouds from the sky," he said. "But like many, I also stopped to see it and it looked like snow,” he said.
Aminu said he chose not to touch the foam because he was unsure what it was, although he saw many other people getting close to it.
"I think the authorities ought to come out to explain what it is so that the confusion among people will die out," he added.
Nesrea confirmed that officials from its Kaduna State Field Office, led by State Co-ordinator Hena Dangari Emmanuel, visited the site after the discovery.
The agency said its officers collected samples of the foamy substance, as well as nearby soil and water from a stream, for laboratory analysis to establish what the material is and whether it poses any danger to people or the environment.
As the investigation continues, the agency has urged the public to avoid any contact with the foam, the nearby water and the surrounding soil to reduce the risk of possible exposure to hazardous materials.
"We have to know what it is first before we can tell people how to handle it or what the dangers are," a spokesperson said.
Preliminary findings indicate that the substance may have spilled after a lorry was involved in an accident. However, officials said the exact type of cargo the vehicle was carrying has not yet been established, leaving the source of the mysterious foam unknown.