A masked man with a sword walked into a a school around 75km from Gothenburg, Sweden and killed a teacher while wounding four students at before being shot by police.

Two boys, 11 and 15, and a male teacher are being treated for serious stab wounds at Trollhättan hospital.

The attacker is also being treated for gunshot wounds in a nearby hospital in the city of Trollhattan, police said.

“The suspect has been shot and is being treated at NÄL (the regional hospital). He is seriously injured and is being operated on,” said hospital spokesperson Niklas Claesson.

Police spokesman Thomas Fuxborg told the Associated Press the attacker was in his 20s and carried more than one weapon, including “at least one knife-like object”.