Sweden's security police Säpo confirmed on Tuesday that they were investigating reports of a potential terror threat directed against Sweden.
"I can confirm that Säpo is working intensively on assessing the information received. It is of such a nature that we cannot dismiss it. We are currently collecting information and intelligence," press officer Sirpa Franzén told the TT newswire.
The news stirred tension in Stockholm, which is set to play host to the Eurovision Song Contest finals in just a couple of weeks.
Although the apparent terror threat was not immediately linked to the event at the Globe Arena, the DN newspaper reported that SVT, which produces the competition, was staying in close contact with police.
"After Paris and Brussels this is of course very inconvenient. Both guests and audience are worried," an unnamed source told the Swedish daily.
Säpo and police confirmed that they were working closely with organizers, who had been filled in on the situation at a meeting with police on Tuesday morning, but did not comment on what had been said.
"It was a scheduled meeting for the special team created ahead of the event at the Globe Arena. Obviously we have shared the information we are able to share," said police press spokesperson Kjell Lindgren.
Earlier in the day, the Expressen tabloid wrote that Iraqi intelligence had said that a group of at least seven Isis terrorists had made their way to Sweden. Säpo did not confirm the report.
Interior Minister Anders Ygeman would not comment on reports of a terror threat.
“We are referring all questions to Säpo,” said his spokesman Victor Harju.
A press officer for Swedavia, which operates ten of Sweden's largest airports, including Stockholm's Arlanda, said it was keeping an eye on the situation, but would not increase security for now.
"The threat level against Sweden has not been upgraded and we have not been given any information. The security situation is the same as before," said Ulf Wallin.
Earlier this year Sweden lowered its terror threat level after raising it briefly in November, days after the attacks in Paris left 130 people dead and during a separate hunt for a suspected terrorist in the Nordic country.
However, the terror suspect police arrested soon afterwards in northern Sweden turned out to be innocent and later demanded compensation from the Swedish government.