The three victims were stabbed early on Monday afternoon inside the Västerås branch of the global furniture giant, with police called to the scene at around 1pm.
"We don't have the complete picture yet, but what we know right now is that none of our staff are among the injured. For now we're focusing on our staff members and customers and are directing all questions to the police, who are investigating at the scene," Daniela Rogosic, a press officer for Ikea told The Local shortly after 3pm.
But police confirmed that two people had died in the incident.
"A man and a woman who were wounded with a knife and later died of their injuries. Another person is seriously injured. A man has been arrested on suspicion of murder," a police spokesperson Victoria Holmgren told the TT news agency.