SINGAPORE - A Primary 3 girl has landed in hospital after falling victim to a prank by a male classmate who secretly added liquid hand soap to her water bottle.

The victim had a fever and bouts of vomiting after drinking from the bottle, reported Chinese evening daily Lianhe Wanbao on Friday (March 24).

A police report has been made and that investigations are ongoing, the police told The Straits Times on Friday.

The male classmate, nine, had wanted to help a female friend take revenge on the victim. On Wednesday, the boy returned to their classroom during recess time to carry out the act, after he heard about how the victim had a falling out with his friend.

All are Primary 3 pupils at a school in Jurong.

About 20 minutes after she drank from the bottle, the victim had a fever and vomited twice in school. The school then told the girl's 36-year-old father to bring her home.

The girl's father told Lianhe Wanbao that their maid was washing the girl's water bottle when she noticed soap bubbles. There was also a strong smell of Dettol.

She informed the girl's father, who later went back to the school to question the teachers, before taking the girl to the hospital.

The girl's father said the hospital had informed the police about the case.

While doctors have told him that his daughter would not be in any danger in the long term, he remains worried about her condition, as she has still been vomiting.

On Thursday night, the girl told Lianhe Wanbao on her hospital bed that she had seen the boy laughing after she drank from the bottle. The boy had also told her earlier that he wanted to "poison" her, but she did not take him seriously.

Later that night, the boy visited the girl at the hospital, accompanied by his 27-year-old mother and a teacher.

The boy stood by the girl's bedside crying, as he told her: "Sorry."

His mother said that her son did not have many friends in school. He decided to poison the girl, at his friend's instruction, as he was worried he would lose their friendship.

She also apologised to the girl's family at the hospital.

The school's principal and a few teachers had also visited the girl and they are offering assistance to the girl's family, according to Lianhe Wanbao.