The attacks happened at around 3pm on Monday in various parts of Tibro, near Gothenburg. The attacker skated from one randomly selected victim to another. His victims included two men in their nineties, one of whom sustained minor knife wounds to the thigh and the other to the lower back.
A woman in her twenties was stabbed in the thigh, although she was not seriously injured. A fourth woman also sustained minor injuries; the man had attacked her as she cycled past him.
The rollerblading attacker, 35, was arrested later in the evening on suspicion of attempted manslaughter. The man, who lives in Tibro, is not previously known to police and is not thought to have known the people he attacked.
“It appears at the moment to have been completely unplanned,” said police spokesman Stefan Gustavsson.