A group of organizations on Tuesday posted an online statement protesting the way authorities responded to accusations from a female high school student that three male classmates spiked her drink with herbal "sex pills".

The senior at Tianjiabing High School in Huangshan, in East China's Anhui province, posted an update on her micro blog last weekend that the boys used philter pills, which are marketed as an aphrodisiac for women.

The NGOs, who work on behalf of women and children, expressed dissatisfaction with local public security and education authorities, who declined to release details about the boys, their motivation for the incident or their punishment.

"We need to know whether the deed was a crime and what the authorities have done to punish the boys," said Li Sipan, a feminist who participated in the joint statement.

The NGOs also urged the quick establishment of effective mechanisms against similar conduct.

The Huangshan Bureau of Education, in its own statement released on Tuesday, responded that the evidence was insufficient for filing a case and the boys had already been punished according to school regulations.

"We have no further information to provide other than the latest statement released on the education bureau's official website", said Ni Wenhua, an official of the municipal government's information department.

According to previous reports, the boys excused their behavior, claiming it was merely mischief between classmates. But the girl said they did it on purpose, likely after learning she had told her friends that she was a lesbian and had a girlfriend. Students spread the information and the boys frequently laughed at her, she said.

She said she was initially told the pills were a cathartic and reported the incident to a teacher. She said the boys told her the next morning that the pills were philters, which was also confirmed by the local authorities in the Tuesday statement.

The student said the boys later threatened to poison her with arsenic in revenge for telling officials what happened.

"Luckily, the philter didn't work due to unknown reasons," she said.

Authorities also said in the earlier statement that the student had forgiven the boys, and no details would be released since all of the students were juveniles and it would be better for all of them to "focus on their studies and get good marks in the pending college entrance exams".