A primary school teacher was taken off teaching duties this week after several parents complained that she had mistreated their children earlier this year.
The parents told The Straits Times that the Gongshang Primary School teacher - who taught science and mathematics - had humiliated pupils by calling them names such as "retarded monkeys" and making a few of them kneel in class or sit on the floor .
The parents said she had also thrown objects - such as a marker which had hit a boy's face - and told another he was "a disgrace to God".
When contacted, the Ministry of Education (MOE) said it is investigating the matter.
"MOE takes a serious view of misconduct by teachers... Teachers who fail to comply with our standards of conduct and discipline will be subjected to disciplinary action," said a spokesman.
Madam Josephine Chua, 43, said her Primary 5 son was made to kneel in class three times this year.
"I found out about this only at the start of this month," said the housewife whose daughter in Primary 3 was also taught by the same teacher.
"The teacher called to say my son had misbehaved. She said she had written something in his learning journal about his behaviour and that I had to acknowledge it. She didn't mention the kneeling."
That evening, her son told her about the kneeling punishment and that it was not the first time.
He was also called "a disgrace to God" by the teacher, who had also threatened the pupils by telling them she knew who complained about her to their parents.
Madam Chua and her husband met the school's principal and vice-principal on Monday.
They were not the first parents to tell the school about the teacher's conduct.
Madam Chua said that up to 10 parents had come forward since March to share with each other and the school their children's encounters with the teacher.
She said that the parents asked the school if the teacher could be suspended or posted to the ministry's headquarters but were told the directive had to come from the MOE.
Madam Joey Hoe, 32, a general manager, said her Primary 3 son was told by the teacher to sit on the floor with the chair as his table during lessons.
"He was probably being chatty or not following instructions," she said.
"There were episodes of her threatening the kids, throwing files in the classroom and shouting and screaming almost every day."
Mr George Cheah, the school's vice-principal for administration, said in a statement on Thursday night that it "takes any misconduct of our teachers very seriously".
"After receiving the parents' feedback, the school leaders met the parents to understand their concerns. Our students' welfare remains our top priority," he said.
"The teacher has been relieved of her teaching duties while investigations are ongoing."
Madam Chua said: "We understand that investigations are ongoing, but it is quite unnerving to know that I put my kids in the school for six to eight hours every day and she is still on the school premises.
"I am surprised that the school didn't take stronger measures earlier when it heard about the incidents."