Two men have been arrested after a man and a woman were stabbed to death at an Ikea store in the Swedish city of Vasteras.
One of the suspects, was initially thought to be a victim and was taken to hospital with serious injuries.
"This looks like a crazy incident," Per Agren of the Vasteras police told a news conference on Monday evening (local time), announcing the surprise development and second arrest.
"We don't know the motive," he added.
The two victims died at the scene, and likely knew each other, but police have no information as to whether the victims knew their attackers, Agren said.
The second suspect - only identified as being born in 1979 - was rushed to the main hospital in Vasteras, 100km west of Stockholm.
Police have not established how he was injured, but became suspicious after officers interviewed witnesses, Agren said.
A younger man, born in 1992, was earlier arrested outside the department store after being identified by witnesses.
The state crime prevention and counter-terrorism organisation Swedish Security Service (Sapo) said it was not involved in the probe.
Earlier, department store manager Mattias Johansson told reporters that those stabbed "appeared to be regular customers", local newspaper VLT reported.
He said no IKEA staff members had been physically harmed, and the firm's focus was on supporting affected customers and staff.