A bus was the first to be shot at on Tuesday evening in Nora, with the driver immediately alerting authorities. Police then classified the shooting as attempted murder, according to the Expressen newspaper.
However, when the drivers of a further three cars and one ambulance called in to report similar incidents nearby, police were forced to cordon off four busy roads in the area and to step up their investigation.
The police eventually found and arrested two teenagers who are suspected of committing the crimes. The teenagers' parents have been notified.
Police suspect that the weapon used was an air rifle, although this is yet to be confirmed.
The severity of the crime rests on the weapon, according to police, with attempted murder not to be ruled out until experts carry out forensic tests.
“We have to test the weapon to see if it's been tampered with and to check the caliber before we decide on the crime,” said Kenneth Johannesson of the Örebro police to the Expressen newspaper.