Police have evacuated properties in Lancashire as they executed an arrest warrant under the Explosives Act this morning.
Lancashire Police said officers imposed a cordon as they arrested a man, 59, at an address on Nursery Close, Leyland, in the early hours and found "suspicious" items.
A local MP said she was being kept updated as officers attended the "major incident", and praised the work of the local force.
In a statement, Lancashire Police said: "We executed a warrant at an address on Nursery Close in Leyland at around 6am this morning (Thursday, June 22nd) and at the address we found a number of suspicious items.
"A 59-year-old man from Leyland was arrested at the scene under the Explosives Act, and he remains in custody.
"Emergency services remain at the scene and a number of properties have been evacuated."
In a statement sent to Lancashire Live, Katherine Fletcher, the Conservative MP for South Ribble, said police placed a "large cordon" that covered a local civic centre.
She said: "I am being kept updated by Lancashire Police about a major incident in the centre of Leyland this morning.
"There is a large cordon around the Broadfield Drive area of the town that extends into the civic centre.
"A man has been arrested following the execution of a search warrant at an address. This is an excellent example of our police working proactively to protect our communities.
"I thank all officers involved for their work today."
Also speaking to the publication, South Ribble councillor Matthew Tomlinson issued a statement of his own.
He said police discovered the house could potentially contain "bomb-making equipment".
He added that officers had placed the cordon as a precautionary measure, and warned it could cause delays across the town.
Mr Tomlinson stressed that "police have just made a discovery", adding there were no explosions or injuries.