The Oyo State Police Command says it has intercepted a truck conveying materials suspected to be explosive in the Sango area of Ibadan, the state capital.
In a statement on Sunday, Ayanlade Olayinka, police spokesperson in Oyo, said the interception followed a stop-and-search operation based on credible intelligence.
Olayinka said the truck driver was arrested alongside 42 items suspected to be explosive materials.
He said Femi Haruna, commissioner of police in Oyo, has ordered a thorough investigation into the incident.
Olayinka said specialised officers from the explosive ordnance disposal (EOD) unit and the chemical, biological, radiological and nuclear (CBRN) unit were deployed to secure the materials.
He added that the deployed units are conducting forensic examinations to establish the exact nature of the items.
The police spokesperson said investigations are ongoing to determine the intended use of the suspected materials.
Olayinka assured residents that there is no cause for panic, noting that updates will be provided as inquiries progress.