Relatives of three-year-old Nausheed Hamid, who drowned in a pond on Patna zoo premises, staged a protest at Sanjay Gandhi Biological Park on Sunday.
The child drowned in a pond in the zoo's children park on Saturday.
Her father, Hamid Murtaza, said: "I came to the zoo yesterday (Saturday) with nine members of my family around noon. After taking a tour of the animal cages, we arrived at the children's park around 3pm. While the children were playing, we were sitting on a platform in the park.
"As we were about to leave an hour later, we could not find Nausheed. We sought help of the zoo staff but none of them was around. Half-an-hour later, a zoo employee found my daughter's body floating in the pond."
Nausheed was rushed to Shashtri Nagar Hospital, around 3km from zoo, where the doctors declared her brought dead.
Murtaza, along with his relatives and neighbours, arrived at the zoo on Sunday seeking an explanation from the director.
"We want an explanation from the zoo authorities how the accident occurred," said Murtaza. "Why is there a pond in the children's park?"
He added: "I found out that the pond is out-of-bounds for visitors. But why isn't there a signboard mentioning it? Why wasn't a single zoo employee deputed at the park where children play?"
The bereaved father, however, had to return without an answer. "We were told that the zoo director was not at his office," said Murtaza, an employee of an automobile spare parts shop in the Exhibition Road area.
"We called on his cellphone but he did not answer. Later, my relatives and friends staged a protest at the zoo gate but no one listened to us," he added.
However, the zoo authorities claimed that they were unaware of any protest. Sanjay Gandhi Biological Park director Abhay Kumar told The Telegraph: "I don't know of any representation from the family of the girl who died at the zoo yesterday (Saturday)."
He also claimed that the accident had occurred because of carelessness of the family. "This is the first time that such an incident has occurred. No one is allowed near the pond that has only knee-deep water. I don't understand how the family members of the girl allowed her to run around without any supervision. If people can't take care of their children what can the zoo employees do?"
However, no police complaint was lodged against the zoo authorities yet.
