NTB reported that the situation is chaotic and unsettled after a major gas explosion shook the mayonnaise factory, Mills in south-eastern province of Norway, Fredrikstad.
Østfold police confirmed the explosion at 17.37.
Injured workers have been transported by a Sea King rescue helicopter from Oslo to the Østfold Hospital.
Communication Manager of the hospital, Anne Grethe Erlandsen told TV2.no that they have received one injured person so far.
A larger area was blocked with fear of more explosions shortly after the explosion. Police also ask people who live nearby to keep away from the site.