Rescuers have found the bodies of two boys who drowned at Blue Dam in Fleurhoff on Sunday, Johannesburg emergency services said on Monday.

"After a 24-hour operation by search and rescue teams, we are relieved to have found them... The difficult task now is telling their parents," spokesperson Percy Morokane said.

He said the boys, aged six and eight, were found on the far end of the dam among the reeds.

"They were both found together among the reeds," he said.

The two boys and a friend went to the dam at 11am. The youngest boy jumped into the water, and when he began sinking the eight-year-old tried to save him.

"Both boys, who were best friends, went under. The third child saw bubbles on the water surface and ran about two kilometres to Meadowlands to inform their parents."

He said parents should take responsibility for the whereabouts of their children.

"We are giving too little regard to safety."