"Police received a call about wounded people at Ikea ... around 1:00 pm. A man and a woman with stab wounds were found at the scene, they later died of their injuries," police statement announced.
"Another person is seriously injured. One man has been arrested suspected of murder," the statement added.
Local newspaper VLT quoted department store manager Mattias Johansson as saying that the three who were stabbed "appeared to be regular customers."
The wounded person is a man aged around 35 who immediately underwent surgery at a local hospital, said Eva Lindahl, a spokeswoman for the regional health care authority, Press TV reported.
There was no indication that the attack was terrorism-related, with Swedish intelligence agency Sapo saying it had not been called in on the case.
The suspect was not known to police and did not have a criminal record, a police spokesman for the Vastmanland region, Per Stromback said.