No one was killed in the two explosions, which police said were retaliations from the biker gang Bandidos against a taxi driver and a man in the Gothenburg restaurant industry.
Both explosions were caused by someone placing a hand grenade behind a tire on the parked cars that detonated after the vehicles backed up.
The Bandidos leader, who was not identified by name, was arrested Wednesday night after a car exploded near a central square in Sweden’s second-largest city, setting fire to several other vehicles parked nearby. Police said the driver of the car suffered only minor injuries.
On Tuesday, a taxi blew up in a Gothenburg suburb, but the driver - who police said had testified against Bandidos in a recent trial - escaped unharmed.