A second person has been arrested in connection with the Stockholm terror attack.

Helga Hullmann, a judge at the Stockholm District Court said: "Police have arrested a person and we have appointed a public defender."

"District Prosecutor Mats Ljungqvist ... made the decision on the arrest," the prosecution authority said in a statement.

The suspect was arrested on a lower degree of suspicion.

On Sunday Swedish police officials said all victims of the attack had been identified, including one British person, one Belgian and two Swedes.

A 39-year-old man from Uzbekistan was arrested hours after the massacre on Friday, and it emerged he had been known to security services.

Jonas Hysing told a news conference the suspect was an asylum seeker who had sought and been denied permanent residency in the Nordic country and was wanted for deportation.

Police also confirmed he had expressed sympathies with extremist organisations including Isis.

"We know that he showed sympathies for extremist organisations, among them IS," Mr Hysing said.