The man gave himself in to police voluntarily and was placed under arrest on Saturday night, reports TT.
“One person was arrested during the afternoon. The 19-year-old man came to police of his own volition,” police spokesperson Lisa Sannervik said.
Sannervik confirmed that the man was suspected of two counts of attempted murder, but did not go into detail regarding why he had chosen to turn himself in.
“That is something we will speak to him about and are therefore keeping it to ourselves,” she said.
The shooting was reported to police at around 9pm on Friday, after which both of the injured men were taken to hospital. One of the men subsequently received surgical treatment.
Sannervik said on Saturday that police investigations into the incident were ongoing.
“Forensic examination of the scene will continue and we will conduct interviews with the injured parties,” she said.
Up to 30 customers are reported to have witnessed the incident at the pizzeria.
A man is reported to have entered the fast food establishment alone before firing several shots and running from the scene.
Police despatched a helicopter as part of an effort to locate the suspect.
The shooting is being treated as part of a crime-connected conflict, reports TT.
But at least one of the two injured men is not connected to that conflict and was hit by mistake, according to a report by local media Upsala Nya Tidning. The man, a student from the Netherlands, is reported not to have suffered life-threatening injuries.
The two injured men are both in their twenties and do not know each other, police said.
The shooting is not the first violent incident of its kind this weekend.
Also on Friday, two men were shot in the Närlunda neighbourhood in Helsingborg. Both were previously known to police.
A 23-year-old man lost his life in that incident, police spokesperson Fredrik Bratt told TT on Friday. No arrests have been reported at the time of writing.
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