A 59-year-old Leyland man arrested under the Explosives Act has now been released on bail.
He was arrested after police searched a home in Nursery Close, off Broadfield Drive, at around 6am on Thursday (June 22) where officers found 'suspicious chemicals' and 'potential explosive equipment'.
He was arrested on suspicion of offences under the Explosives Act but was bailed yesterday evening.
The investigation is ongoing and being led by Counter Terrorism Policing North West with support from Lancashire Police and partner agencies.
At 6am on Thursday, Lancashire Police carried out a pre-planned warrant at a house in Nursery Close - a quiet cul-de-sac of seven detached homes off Broadfield Drive, opposite the fire station and next to St Mary's Church.
When officers entered the home, they found a 'quantity of items of concern'. These include what police described as 'suspicious chemicals and potential explosive equipment'.
A 59-year-old man from Leyland was arrested at the scene on suspicion of offences under the Explosives Act and taken into custody.
A major incident was declared and a 100m safety cordon was immediately placed around the vicinity of the home while neighbours were taken to an evacuation centre.
The Civic Centre council offices, Job Centre and a number of homes and businesses in the cordon area were evacuated and the area remained locked down while the military's Explosives Ordnance Department (bomb squad) was called to the scene.
The investigation is being led by Counter Terrorism Policing North West with support from Lancashire Police and partner agencies.
Senior Investigating Officer Detective Chief Inspector Clare Devlin said the investigation is still in its early stages but said "there is currently no evidence to suggest that any other persons or locations are involved".
Speaking at a media briefing at the police cordon outside Nursery Close yesterday, Det Chief Insp Scott Waddington added: "We're going to interview that suspect and relevant questions will be asked. We will try to gain more information.
"What we are confident of is that the evidence would suggest there is no other persons involved, there is no other addresses involved, and we're very comfortable at this moment in time with the investigation so far."
Supt Gary Crowe of Lancashire Police added: "We have a significant policing and emergency services presence at the scene and we are asking people to avoid the area and find alternative routes where possible.
"It is expected the searches will be ongoing and continue tomorrow. Residents should expect some disruption while we continue our searches and I thank them for their cooperation and support so far.
"We appreciate that this will be concerning for the community of Leyland but we want to reassure all residents we are working extremely hard with all our partners to make the address safe and bring this matter to a swift conclusion."
When asked if he was surprised at what was discovered inside the home, he said: "I don't think we were surprised because we had got the warrant out for a reason, so we had half an idea of what we would come across."
The cordon remained in place until late into the evening while work continued to make the the potentially explosive items and materials safe.