A quantity of chemicals and drugs were recovered from an address in Ashington.
Police were called to an address in Chestnut Street on Wednesday after reports of a known male with a suspected firearm.
Officers attended the address and following a search of the premises a quantity of chemicals were recovered and a local man was arrested for possession of controlled drugs.
The man is still in police custody.
Local officers remain in the area to carry out enquiries and provide reassurance and specialist officers are continuing to search the address.
Chief Superintendent Sharon Scott said: “I would like to reassure local residents and the wider public that we are treating this as an isolated incident and they are not at any risk from the items we have recovered.
“A local man has been arrested and is currently helping us with our enquiries and we aren’t looking for anyone else in connection with this incident.
“We would also ask that if anyone has any information that may help with our enquiries to please contact us.”
Anyone with any information is asked to contact police on 101 or independent charity Crimestoppers anonymously on 0800 555 111.