Four students and one adult have been injured after a masked man with a sword attacked a school in Trollhättan, Sweden.

Police told Swedish news agency TT there was "considerable confusion" at the school, which had been evacuated.

"We have a number of people injured," Stefan Gustafsson, from the region's police force, said.

The attacker was reportedly shot by police.

"His condition is unknown", Mr Gustafsson added.

One person has been hospitalised with serious injuries, P4 West reports.

It is unclear whether that is the attacker or a victim.