At least two people were killed at a school in northern Slovakia after a student attacked a teacher and two classmates with a knife, emergency services and police said on Thursday, Reuters reports.

Slovak emergency services spokesperson Danka Capakova told Reuters that several crews had been dispatched to a high school in Spisska Stara Ves.

"At least two people are dead and one injured," she said

Police said in a post on Facebook that a student attacked a teacher and two classmates.

Several emergency medical crews were at the scene, but the number of injured was not yet known, broadcaster TA3 reported.