The bomb threat, which arrived by email, stated that an attack was planned against the newspaper's Nyköping offices and was sent at around 9.30pm on Saturday.
The email contained specific demands regarding the newspaper's reporting on the bombing of an apartment in the town on March 2nd in which two people died. If the demands weren't met then the newspaper would be bombed, the email is reported to have warned.
The police bomb squad arrived at the offices at around 2am on Sunday and worked until 5am in order to secure the building. The police have confirmed that nothing suspicious was found.
"But we are going to continue surveillance of the building until further notice," said Mikael Ericson at Sörmland police to the TT news agency on Sunday morning.
A man was on Friday remanded into custody on suspicion of having carried out the bombing on an apartment in the Brandkärr neighbourhood of Nyköping on March 2nd. Two 27-year-old men died in the explosion.
The man has admitted to knowing the two victims but denies that he had anything to do with the attack. Police do not suspect any political motive.