STOCKHOLM, Aug 10 (Reuters) - A man and a woman were killed and a third injured in a knife attack at an IKEA store in the Swedish city of Vasteras on Monday and two suspects were arrested, police said.

One of the suspects was apprehended at the scene and the second, who was seriously injured, was picked up at a hospital a few hours later, commanding police officer Per Agren said at a press conference. How he was injured was not clear.

The suspects were two men born in 1992 and 1979 who probably knew each other, Agren said. They had no connection with the victims and the motive for the attack was not known, he said.

Officers were called to the store at 1 p.m. (1100 GMT) and found three people with knife injuries, police spokesman Per Stromback told reporters outside the IKEA outlet about an hour west of the capital, Stockholm.