Customs officials found the object on a train in Malmö and the police bomb squad was called in on Tuesday afternoon, at around 6.30pm.
“Police were called to the scene and were able to detain an 18-year-old man. We have also detained a man aged 25 who was located in another place but who we think was connected to this,” said police press person Filip Annas.
Police could not say exactly what kind of object was found on the train, since investigations were ongoing.
“I don't know at the moment, but we are beginning to get an idea of what it is,” said Annas.
By later on Tuesday evening, the police cordons had been removed and trains were continuing to run as normal.