"After we had taken out around 50 balls, the remaining ones formed a line and we took those out in one go."
Magnetic balls are popular among children and a pack of about 200 can be bought online for under US$10.
But incidents such as this have prompted doctors to warn parents against buying them as a toy for their children.
Tao said that doctors at the hospital encountered two or three similar cases per year, with the boys tending to be aged between 10 and 15 and the inserted items including electric wires, needles and, in one case, an 8cm ear scoop.
He said that a boy's penis could allow an object with a diameter of up to 7-8mm to pass through it.
How Chinese doctor removed magnets from boy's stomachIn July, doctors in Zhumadian, in central China's Henan province, removed a 40cm headphone wire from an 18-year-old boy, Dahe Daily reported. The patient was quoted as saying he had inserted it into his penis a year earlier and, although it was painful, he was too embarrassed to tell his family.
A 13-year-old in Harbin, in Heilongjiang in the country's northeast, had to have surgery last year to remove a 10cm electric wire from his penis. Doctors found the wire knotted in his bladder, a local television station reported.