Upsala Nya Tidning writes that the alarm came in to the rescue service at noon on Saturday. He was taken to hospital by ambulance helicopter after being found in the water.
It was relatives who alerted the rescue services that the person was missing, says Örjan Lokebron, emergency response leader at the rescue services, to UNT.
The Academic Hospital wrote in a statement this afternoon that the boy is being treated in an intensive care unit with life-threatening injuries.
The beach was evacuated after the alarm, but was later able to reopen.
