British police planned a second controlled explosion in the southwestern city of Bristol on Friday, following the arrest of a 19-year-old man on terrorism charges.
About 30 people were evacuated from their homes when a bomb disposal team exploded a first suspect package in a quiet residential street in the early hours of Friday.
Avon and Somerset Police said they planned a second detonation late on Friday night.
"We appreciate that this means continuing disruption to the residents of that area but I am sure they will appreciate that everything that is being done is with public safety as the paramount priority," said Assistant Chief Constable Jackie Roberts.
Roberts said a man aged 19 was arrested on Thursday afternoon on terrorism charges.
She said he remains in custody for questioning and confirmed that material from the first blast was retrieved for analysis.
"This is likely to be a prolonged, complex and sensitive inquiry which may take some time," Roberts told a news conference.