Forty-four young people were taken to hospital on Monday following a suspected food poisoning outbreak at a Jockey Club camp in Tai Po.
An organiser said the group, aged 11 to 18, were suffering from diarrhoea and vomiting.
The children had been camping at the Hong Kong Award for Young People Jockey Club Duke of Edinburgh Training Camp in Lam Tsuen since Saturday, the organiser said.
FoodWorld 