SEOUL, May 17 -- It was meant to be a joyful morning of games and laughter, but before a South Korean elementary school could begin its annual sports day earlier this week, the children did something unexpected - they apologised.

A now viral video shows the primary schoolers gathered on a field near an apartment complex, bowing their heads and chanting together: "We're sorry. Please let us play just a little today. Thank you."

The video, originally shared on Instagram and widely circulated online, is titled "These days, elementary school sports days start with an apology" and has been reported by South Korean media outlets.

It captured what was supposed to be a cheerful event but instead revealed a growing tension between schools and r...