HONG KONG, May 29 -- A Hong Kong secondary school principal has resigned after a video showing him swearing at security guards during a student trip to Singapore sparked widespread backlash online.

According to the South China Morning Post, Lee Cheuk-hing submitted his resignation yesterday as principal of San Wui Commercial Society Secondary School in Tuen Mun.

School manager Edmund Wong Chun-sek confirmed the resignation, but said the school's board of directors would need to meet before deciding whether to accept it.

In a video released later yesterday, an emotional Lee repeatedly apologised to the public in Hong Kong and Singapore, acknowledging that his conduct had fallen short of the standards expected of him.

"As a principal, I...