Britain urged its citizens traveling to Sweden on Sunday to remain cautious of a possible terrorist attack following the Koran burnings by anti-Islam activists last month.

Reuters reported that Britain’s updated travel advice noted Swedish authorities had already stopped planned attacks and made some arrests since the burning.

The update said “you should be vigilant at this time,” adding that “terrorists are very likely to try and carry out attacks in Sweden.” It went on to note that places visited by tourists could be potential targets for such attacks.

Sweden’s National Security Advisor Henrik Landerhholm acknowledged Britain’s travel advice, confirming that there have been increased threats to the Scandinavian country since the burnings occurred last month.

Landerholm noted three primary incidents that contributed to the risk assessment in the country. It started with the Swedish embassy in Iraq being stormed on July 19. There was also an attempted attack on its embassy in Lebanon on August 9, and then the shooting of an employee at a Swedish consulate in Turkey on August 1.

Burning a Koran in Sweden is not illegal. It is allowed under the nation’s free speech rules, but Muslims perceive the burning of their holy book as blasphemy. The report also mentioned that the US government has put out its own travel advice for those going to Sweden.