A gunman who killed 11 people, including himself, at an adult education centre in central Sweden may have been a student at the school, police said on Thursday, as they described chaotic scenes after the country's deadliest mass shooting as being like an "inferno".

OREBRO, Sweden (Reuters) - Swedish police found three rifles in the adult education centre in Orebro where a gunman killed 11 people and wounded several others this week in the country's deadliest mass shooting, a spokesperson said on Thursday.

The attack on Tuesday - described by Sweden's prime minister as the "worst mass shooting" in the country's history - happened at a school for adults.

By Johan Ahlander and Simon Johnson OREBRO, Sweden (Reuters) -Swedish police found three rifles near the body of the gunman amid a chaotic scene they described as an "inferno" after 11 people were killed and several wounded in the country's deadliest mass shooting,

The police responding to the attack encountered firing so intense that they struggled to tell how many gunmen were on the scene, an official said.

Swedish police said the gunman in the country’s worst mass shooting was connected to the adult education center where he opened fire Tuesday, killing 10 other people. Police later found him dead.

Salim Iskef, 29, fled the Islamic State and Syria to form a better, more secure life in Sweden, only to be gunned down this week in the worst mass-shooting in Swedish history.

Swedish police confirm around 10 people were killed at a school for adults on the outskirts of Stockholm. The gunman is believed to be among the dead.

Sweden is reeling from the country's deadliest mass shooting this week as investigators continue to look into the gunman's motive