Swedish police announced on Tuesday that at least five people were injured in a deadly attack at a school in the city of Örebro, located about 200 kilometers west of Stockholm.

The police confirmed that the incident is linked to previous threats of a violent assault, and the situation is still developing.

Swedish Justice Minister Gunnar Strömmer described the reports of violence in Örebro as “extremely serious,” noting that the government is closely monitoring the situation.

No additional details regarding the attacker’s identity have been disclosed so far.