About 100 homes were evacuated as a precaution after the discovery of “potentially hazardous or combustible materials” during a police search.
Essex Police had been carrying out a search warrant at a property in Rokescroft, Pitsea, on Tuesday, “following intelligence received”.
A 100m exclusion-zone cordon was placed around the address while bomb disposal teams worked on site and specialists recovered “items of concern”.
A 37‑year‑old man from Pitsea has been arrested on suspicion of making or possessing explosives under suspicious circumstances and remains in police custody, the force said.