According to the news agency AP, one teacher has been confirmed dead following the attack at the Kronan school in Trollhattan, north of Sweden’s second-largest city Gothenburg.
The masked suspect is also said to be in a serious condition after he was shot by police.
Another four students are reported to have been injured.
Police said they were initially called to reports of a masked man, armed with a sword, on the premises and that one person had been attacked at or near the school cafeteria.
Four people have been admitted to the NAL hospital in the nearby town of Trollhattan, a spokesman said.
"The assailant is being treated for gunshot wounds," he said. "The other people treated at the hospital are young but not kids. "Some of them have serious injuries and are being operated on.
"One person is deceased at the scene," the spokesman said.
source: Sky News