Several people have been detained in Gothenburg and its suburbs on suspicion of being related to the bomb threat in Sweden's second largest city, Svenska Dagbladet said on Sunday.
On Friday, police issued a bomb alert for Saturday. A "reliable source" tipped police that a blast is being plotted in the city's downtown area, RIA Novosti reported.
Arrests were carried out throughout Saturday.
Two suspects remain in custody, while others were released. Neither the names of the detainees, nor their total number were disclosed. Possible motives behind the attack also remain a mystery.
According to the TV4 report, three people were arrested in Gothenburg's suburb of Angered, and one person was apprehended in the city.