“She had sustained knife injuries. The woman was found dead in the apartment; the suspected attacker was arrested close to the scene shortly afterwards,” said police spokesman Björn Engström.
The woman was found dead in the apartment on Sveavägen in the centre of the capital.
The man, who is suspected of murder, was being questioned on Friday afternoon at Norrmalm police station. Police confirmed that the man is 18.
“I do not have full information about the woman’s identity, but she was of a comparable age,” said Kjell Lindgren, a spokesman for Stockholm Police.
He said that “there are many indications” that the man and woman knew each other, but said he did not know the nature of their relationship.
Police were carrying out a forensic examination of the apartment on Friday afternoon
“We will then carry out a medical examination of the arrested man. Material will also be given to prosecutors so that a decision on detention can be made.
It is not so far clear whether the man is previously known to police.