At least three people were injured, including one seriously, in an "indiscriminate" attack on Friday in southeastern Norway, Norwegian police said, suggesting that the toll could increase.
The assault happened in a valley called Numedal, in the village of Nore according to Norwegian media.
On Twitter, local police then quickly announced that the suspect had been arrested, stating that they had "control over the alleged perpetrator" of the attack, without providing further details.
She has not, either, given, at this stage, the reasons for the attack.
Police still on the scene
According to witnesses quoted by the Norwegian media, numerous police patrols and ambulances, as well as three medical helicopters, were dispatched to the scene.
The area where the events occurred is located north of Kongsberg, a town where a bow and knife attack killed five people last October.
Its author, a Dane suffering according to experts from psychiatric disorders, has been on trial since Thursday in Norway.