Police said on Monday they are looking for a man suspected of pushing a boy he didn't know into the sea in To Kwa Wan last Saturday.

Officers said the man, believed to be in his 20s, might have pushed the nine-year-old from the back when they were at Hoi Sum Park.

The force said the boy was fishing with his mother at the time, and he managed to swim ashore on his own.

He suffered cuts to his hand and kneecap, and was conscious when taken to hospital.

The case has been classified as assault occasioning actual bodily harm.