Police used smoke grenades before carrying out searches of the rooms in the hotel in Stockholm's central Odenplan district, according to Aftonbladet.
“In the operation, police forces used the tools which were needed, since the arrested suspects were thought to be armed,” Carina Skegerlind, a police spokesperson, told TT.
Hotel staff reported the men to police after they suspected they may be armed. The three have been arrested on suspicion of illegal weapons possession, though police have not confirmed the type of weapons involved.
Some rooms were evacuated during the search, but some guests were able to stay in their rooms, according to the hotel's receptionist.
The operation began at 6.30 pm on Wednesday evening, and by 8.30 pm there were still some police officers at the hotel. By then, all guests had been allowed to return to their rooms.
“No one was injured in connection with the arrests, as far as I could see,” the receptionist said.