SINGAPORE - Racial Harmony Day is not just another event on the school calendar, but a reminder that Singapore's diversity is a strength, and harmony must continue to be instilled and built up, Singapore's top leaders said on Wednesday (July 21).

President Halimah Yacob said in a Facebook post: "We want our children to be aware that we live in a diverse society and that our difference is a strength and a cause to celebrate.

"By exposing them to such values at a young age, we hope to build a strong foundation for their empathy and understanding of the different races in our society throughout their lives."

Prime Minister Lee Hsien Loong noted that the day is commemorated every year "not to proclaim that Singapore has 'solved' this problem, but to remind ourselves this is something we need to continue working hard on".

"56 years after independence, race remains an urgent and sensitive issue for us," he wrote in a Facebook post.

July 21, 1964, was when the first of two race riots within six weeks took place in Singapore, eventually leading to 36 deaths and injuries to more than 500 people that year.

This served as a reference point for PM Lee, who said it showed him what could happen if Singapore failed to uphold racial harmony. "That has shaped my world view," he said.

PM Lee described racial harmony as an ongoing process evolving and taking on different aspects and complexities with each generation. "Also our discussions are increasingly influenced by what happens elsewhere, in very different societies," he added.

He noted that several racist incidents that went viral recently have provoked strong reactions and soul searching about the discrimination that various groups encounter in Singapore.

While the public debate this sparked has sometimes been uncomfortable, it has been helpful in airing the issues and reminding Singaporeans of the fundamental importance of racial harmony to the nation, he added.

In 1998, the Ministry of Education began marking July 21 as Racial Harmony Day - with schools holding activities to educate students on race and values such as respecting differences.

The challenge, said President Halimah, is to ensure that Racial Harmony Day does not become just another event on the school calendar to be celebrated every year, but with little meaning.

"For it to be truly significant, schools will have to think of how to instil the teaching of these values in their everyday curriculum, so that students can better appreciate the meaning of diversity and have meaningful conversations on race and religion in a safe environment," she noted.

"I hope that our students will find their school journey more meaningful and fulfilling through their interaction with students of different races."