A first suspect has been officially identified as a 39-year-old man from Uzbekistan.
Stockholm: A second suspect was arrested today in connection with the Stockholm truck attack that killed four people and injured 15, a district court said.
"I can confirm that a second person has been arrested," Stockholm district court judge Helga Hullman said.
The new suspect, whose identity was not disclosed, is being investigated about a "terrorist crime (by committing) murder," Karin Rosander, spokeswoman at the Swedish Prosecution Authority told public broadcaster SVT.
The prosecution has until Wednesday to ask a court to remand the suspect in custody, Rosander said.
A first suspect has been officially identified as a 39-year-old man from Uzbekistan and "applied for a permanent residency permit in 2014", a request later rejected, police said on Sunday.
On Friday, the 39-year-old is alleged to have barrelled a stolen beer truck several hundred metres (yards) down the bustling pedestrian street Drottninggatan in the heart of Stockholm.
The vehicle mowed down shoppers before slamming into the facade of the busy Ahlens department store.
The motive for the attack is not known.
Thousands of people were to gather in central Stockholm Sunday for a "Lovefest" vigil against terrorism.