The man was attacked at 2am on Sunday on the Klaraberg viaduct in the centre of the capital. The police arrived to find two boys, aged 16 and 17, hitting the man. He was taken unconscious to hospital with serious head and facial injuries.
Police say he has multiple brain haemmorages and is in a very serious condition. The two boys have been arrested on suspicion of serious assault, police say.
It is so far unclear why the boys attacked the man.
“There seems to have been some kind of a disagreement at a bus stop,” said police commander Ola Törndal.
The man was on Sunday being treated for his injuries at the Karolinska University Hospital. At lunchtime he was sedated in preparation for a brain scan.
There were several witnesses to the attack.