POLICE who arrested two men in Torquay under the Terrorism Act were searching four more locations on Friday afternoon.
The two men, one of them aged 18, were being questioned at an undisclosed location in the West Country.
Residents in Lymington Road had been evacuated on Thursday and the road cordoned off while explosives experts searched the address.
Investigating Sergeant Louise Costin said: “There are four locations due to be searched in connection with the two suspects.
"They may conclude today or they may go into the weekend.”
She could not confirm the locations of the premises being searched.
The two suspects are due to be formally interviewed about the alleged offences by detectives from the Major Crime Team.
Officers from the Counter Terrorism Unit are also involved.
Police insisted there had been no "imminent threat to any person or property in the local area".
Devon and Cornwall's assistant chief constable Sharon Taylor said the force had detained two "local men" but was not looking for anyone else.
She said there was "nothing to suggest" the men were involved in anything outside the local area.
"The investigation is at an early stage – we will be taking a couple of days to interview them and gather the full picture," she added.
An 18-year-old man from Torquay was arrested on Wednesday on suspicion of criminal damage related to a spray-painting.
Following interviews with the man – who was also questioned about a series of arson attacks in the town – a warrant was issued to search an address in Lymington Road on Thursday, which required the evacuation of a small number of neighbouring properties.
A second man, aged 20, and also from the town, was later arrested and both were held under Section 41 of the Terrorism Act 2000, which allows a police officer to arrest anyone he "reasonably suspects" to be a terrorist.
No explosives or bomb-making equipment were found but information found in the house raised the alert.