UPDATE 8 August: All of the detained Tehran "water fighters" --- the number is estimated to be 10 --- have been released on bail after they were charged with "anti-regime propaganda".
UPDATE 2100 GMT: Mardomak reports that 30 people have been arrested in Bandar Abbas in southern Iran over a "water pistol fight".
UPDATE 1600 GMT: TehranLive have now withdrawn the photographs which we have used in this entry. Because this may have been done to protect the identity of the adults in the water fight, we are also withdrawing the pictures of those who could be detained.
UPDATE 0650 GMT: Thirty youths playing water games in a park in Kermanshah have been arrested by morality police forces "for guidance"
Forget all the political conflict inside Iran, the hot story for the international media this week has been how the hot Tehran weather --- and a water fight in a park --- led to the arrests of young men and women.