Residents were left terrified after a controlled explosion was carried out at a block of flats.
Emergency services were called to Fairbairn Street in Dundee at 6pm on Wednesday.
Substances were found in a flat after a 65-year-old man was detained in relation to telecommunication offences.
Officers called the bomb squad and a controlled explosion was carried out in grassy area outside.
Other items have been seized to be investigated by forensic teams.
Residents in the block said they were scared during the incident.
Ruth Williamson said: "Myself and my two daughters have been terrified.
"My nine-year-old was sobbing and it took ages to get her settled, she wanted to know what was happening.
"All I could say was 'I don't know'."
Superintendent Graeme Murdoch said "We understand that it is always concerning for the community when there is this level of police activity, and we require the advice and services of our EOD colleagues.
"However, public safety remains our highest priority and in this case that has been no different, and we have tried to balance this with the impact on local residents.
"I would seek to reassure all residents in Fairbairn Street and the immediate vicinity that there is no ongoing threat to their safety."
He added: "I can now confirm that following a full search we are satisfied that the property concerned is completely safe and we are in the process of advising affected residents that they are free to return to their homes."
Anyone with information is asked to contact 101.