Melioidosis, a bacterial infection, was responsible for killing at least nine monkeys at a Hong Kong zoo, authorities said, as a further two died over the weekend, taking the total to 11 in the past week.

Nine monkeys who died in Hong Kong's oldest zoo in two days this week had been infected with an endemic disease, possibly after some digging work near their cages, officials said on Friday.

The animals contracted melioidosis, possibly after some digging work near their cages, that later caused them to develop sepsis, officials said.