The bomb squad cordoned off an area of Sheffield after police arresting a man found a number of "devices" on him.
Officers were called to Sandford Grove Road in Nether Edge on Wednesday morning following reports of a man acting as though he was drunk.
The area was sealed off as a precaution after arresting officers found a number of devices on him, a spokeswoman said.
A search of nearby houses uncovered a total of 13 devices, all of which were made safe by bomb disposal experts.
Police did not believe there was any danger to the public but cordoned off the Sandford Grove Road and Marden Road areas, close to where the man was detained, as a precautionary measure.
Superintendent Keith Lumley said the devices, which were about the size of a cigarette lighter or lipstick holder, had the appearance of being explosive.
"The individual was arrested as a result of his conduct and behaviour. Subsequently he was searched and a number of devices were found.
"As a result a number of searches were carried out at houses in the vicinity of where he was arrested and more devices were found.
"All together about 13 devices of different constructs were recovered. All have now been made safe by the bomb disposal teams."
He said the incident was not related to terrorism and was being treated as a "domestic issue".
"It may well be someone who has an over-enthusiastic interest in making their own fireworks, that's the scale of which we're talking.
"But they could still cause significant damage," Mr Lumley added.