Explosives, guns and drugs have been found by police during a search of a property which led to 150 homes being evacuated and a 70-year-old man arrested.
Police attended a property in Worle, near Weston-super-Mare, on Wednesday morning to arrest a man on suspicion of fraud by false representation.
But officers conducting an initial search of the house raised the alarm after coming across suspected explosives and other suspicious items.
The man has since also been arrested on suspicion of possessing explosive substances and was taken into custody.
Specialist explosive ordnance disposal (EOD) officers were called to the scene at 12.30pm and a 100m cordon was put into place, prompting the evacuation of 153 homes.
After the bomb squad arrived at 2.15pm, there was an initial delay to them entering the residence to begin working until everyone had been safely moved from within the exclusion zone.
They eventually entered the property at around 7.30pm and 'tubs suspected of containing explosives' with any explosive material were subsequently destroyed.
Officers also found a firearm, an air rifle and drugs at the property, Avon and Somerset Police said in an update this afternoon.
Police attended a property in Worle, near Weston-super-Mare, on Wednesday morning to arrest a man on suspicion of fraud by false representation
Officers found suspected explosives during their initial search, and later also recovered a firearm and an air rifle from the scene
Emergency services on the scene in Worle near Weston-Super-Mare amid the large emergency response
Searches take place at the property - more than 150 homes were evacuated after a 100m cordon was put in place
The cordon was lifted at around 6.15am this morning and residents were allowed to return home.
Following the searches, another location of interest was identified and an EOD unit has attended a non-residential site off the A370 near Hewish this morning.
Searches concluded at around 10am and were negative and the EOD team has since left the scene.
A rest centre was set up at Castle Batch Community Centre, later moving to The Campus in Weston-super-Mare. North Somerset Council said it supported nearly 40 residents, including almost 30 who slept at the community centre overnight.
North Somerset Policing Superintendent Jen Appleford said: 'I recognise the significant impact this incident has had on residents who were evacuated from their homes last night, and on those living near the cordon.
'Our priority is always to protect the public and, in situations like this, we sometimes have to make difficult decisions to ensure everyone remains safe.
'What began as a routine arrest attempt yesterday quickly developed into a significant multi-agency response involving police, fire and ambulance services, the military's Explosive Ordnance Disposal Unit, alongside colleagues from the NHS and North Somerset Council.
'Our dogs unit, specialist search and operational support teams were utilised for this incident and neighbourhood policing and patrol teams supported with the evacuation and cordon.
'During an initial search of the property, officers located tubs suspected of containing explosives, together with other suspicious items. As a precaution, specialist EOD officers were called to assess the scene.
'While we recognise that evacuating your home is significant, it is an essential part of incidents of this nature and EOD are unable to conduct their searches until the cordoned area has been made safe.
'Officers and EOD encountered a delay in entering the property to commence searches due to issues with evacuating individuals from within the cordon, but searches were able to commence at around 7.30pm.
'Following a detailed search of the address, a number of explosive substances were recovered and safely removed. Additional items, including an air rifle, firearm and drugs, were also located and seized.
'I would like to thank residents for their patience and understanding while this complex operation was carried out. I also want to thank our partner agencies for their support throughout the response and to a number of businesses who showed true community spirit in opening their doors, offering food and refreshments for those impacted.
'The suspect remains in police custody and enquiries are ongoing. We understand there may be concerns within the community, but we would like to reassure people that there is currently no wider risk to the public and we believe this to be an isolated incident.
'Officers will remain in the area while investigations continue and we would encourage anyone with information who may be able to assist our enquiries to contact us.'