Around 30 people were evacuated from neighbouring homes during the operation in Westbury-on Trym, Bristol.
Following his arrest yesterday afternoon, the man was taken to a nearby police station and a warrant was executed to search his home.
“We would like to reassure people that this arrest has been made at this stage to prevent harm,” said assistant chief constable Jackie Roberts.
“Public safety has been our paramount priority over the past 24 hours.
“We are very grateful for the co-operation of all the relevant agencies and of those people who have been inconvenienced by this operation.”
She warned that the police inquiry is likely to be prolonged, complex and sensitive, and that it “may take some time”.
People from 14 neighbouring homes were evacuated for the explosion, which was carried out by explosives experts at 2am.
“It is unlikely that those who have been evacuated will be able to return to their homes until much later today at the earliest but I am sure that they will understand that this inconvenience is to ensure their safety and welfare,” Roberts said.
Anyone with information that could help police is urged to contact Crimestoppers on 0800 555 111.