The St Margaret's Secondary principal in the Hair for Hope incident has now allowed the five girls involved to go wig-less after discussion with the students, said Education Minister Heng Swee Keat in a post about the incident on his Facebook page on Wednesday.

"I am happy to learn that yesterday, Mrs (Marion) Tan and her teachers spoke with the students who participated in Hair for Hope," Mr Heng wrote.

"The girls shared with their principal the learning they have had through this experience. Mrs Tan, on her part, has also reflected on her decision, and understood that the girls wanted to show empathy and solidarity with cancer patients which entail the experience of going bald.

"With this in mind, she has supported all five in their wish not to conceal their shaved heads. I am glad that the principal, teachers and students of St Margaret's Secondary School have resolved this and will move on from here," he said. Last week, the St Margaret's students who had their heads shaved for the Hair for Hope charity event in support of children with cancer were taken to task for not wearing wigs after they had promised to do so.

In his blog post on Wednesday morning, Mr Heng added that the teaching community was very proud that the students had shown great character by showing solidarity with those afflicted with cancer. "It is not easy for a teenage girl to shave her head - I fully appreciate and applaud the commitment it shows," wrote Mr Heng adding that the Ministry wants schools to nurture young people with a natural empathy for those who have known suffering.

He noted that Mrs Tan felt the same way and did give her support to the students to join in the charity exercise but on condition that the girls would don wigs in school. While some may say the school is being rigid, he said he understood the principal's rationale for asking the girls to wear wigs.

"She was concerned students of St Margaret's should present themselves within the school's guidelines. However, it is reasonable to ask if and how exceptions could be made, under special circumstances like the Hair for Hope cause. Or, are there other ways of showing support that are compatible with the school's rules and ethos?" he wrote.

Mr Heng noted that schools had no issue with students having a heart but was also trying to teach the girls that character is seen in how we honour commitment.

"This, then, is the real heart of education, that everyone appreciates there is a learning moment in every situation, in every decision we make, in every promise we pledge," he said.