A man has been arrested under the Terrorism Act after potentially explosive materials were seized at a house in East Yorkshire.
The 31-year-old has been taken to a police station in West Yorkshire for questioning by officers from the counter-terrorism unit, police said.
The materials were found during a house search as part of a separate criminal inquiry in Pasture Road, Goole.
Material removed from the house has been sent for forensic testing.
As a precautionary measure, Humberside Police officers cordoned off the immediate area while a thorough search was carried out.
"The property presents no risk to local residents and the police cordon has now been lifted," a Humberside Police spokesman said.
The suspect was initially arrested under the Explosives Act on Wednesday but has now been arrested on suspicion of offences under the Terrorism Act 2000, police said.
Ch Supt Pat Geenty, Divisional Commander for the East Riding of Yorkshire, said: "This is an ongoing investigation led by the counter-terrorism unit (Leeds), supported by officers from Humberside Police.
"I recognise local people may have concerns as a result of this arrest and our neighbourhood policing team will be out in the area as usual to speak to anyone who may have concerns.
"Local police officers are meeting with representatives of all sections of the community to keep them as informed as we can about the investigation.
"We would ask people to remain alert and vigilant but not to be alarmed and we are grateful for the assistance, support and understanding of people locally."