The Hong Kong government reacted with anger on Monday after a popular pro-democracy song was played in place of the Chinese national anthem for the city’s team at a rugby sevens tournament in South Korea.

The city’s sports teams play the Chinese national anthem, but before Hong Kong faced South Korea in the final of the Asia Rugby Sevens Series in Incheon on Sunday, “Glory to Hong Kong” was broadcast instead.

Written by an anonymous composer during the large and sometimes violent protests of 2019, the song became an anthem for the city’s now-defunct pro-democracy movement.

The Hong Kong government “strongly regrets and opposes the playing of a song closely associated with violent protests and the ‘independence movement'” in place of China’s national anthem, it said in a statement.

“The national anthem is a symbol of our country. The organizer of the tournament has a duty to ensure that the national anthem receives the respect it deserves,” said a government spokesman.

In a subsequent statement, the Hong Kong government said the city’s chief secretary, Eric Chan, met with Seoul’s consul-general on Monday “and called on the Korean side to fully investigate the incident and related responsibilities.”

The mix-up has embroiled Hong Kong’s rugby team in a political row.

Video of the incident showed the players showing serious faces and not responding to the wrong song being played.

Junius Ho, a fiery pro-Beijing-Hong Kong MP, attacked the players for this election.

“They just allowed the country to be humiliated,” Ho wrote on Facebook. “They failed completely and lost our trust. Now the only solution is to disband the Hong Kong rugby team.”

Ronny Tong, who serves in Hong Kong’s cabinet, said the incident “could not be a negligent error” and likely violated the city’s national security law.

China imposed a sweeping security law on Hong Kong in response to the 2019 protests to stamp out dissent.

Its wording claims universal jurisdiction – Hong Kong and China authorities say they can prosecute people for national security violations committed abroad.

“It’s hard to believe that the incident isn’t about helping people in Hong Kong,” Tong wrote on Facebook.

The Hong Kong government said police have launched an investigation.

Asia Rugby said the mistake was a mistake and apologized to both the Hong Kong and Chinese governments.

“The incident stems from a simple human error by a junior member of the local organizing committee, who played a song downloaded from the internet instead of the correct anthem,” tournament organizers said.

After the final – which Hong Kong won – Asia Rugby said the stadium broadcast apologies in Korean and English and then played the Chinese national anthem.

The Hong Kong Rugby Union said they had “expressed our deepest concern and regret over this incident” to the tournament organizers.

“While we accept that this was a case of human error, it was still unacceptable,” HKRU said.

China’s “March of the Volunteers” emerged from the Communist Party’s struggle to liberate the country from Japanese occupation and begins with the rallying cry “Rise up! You who refuse to be slaves”.

It was played in Hong Kong’s handover to China in 1997, when colonial Britain left.

Before the 2019 pro-democracy protests, football fans in Hong Kong often booed the national anthem, infuriating Beijing.

Hong Kong later passed a law banning insults to the anthem. The first person sentenced under this new law was jailed last week.

“Glory to Hong Kong” is a similarly stirring composition and was secretly recorded by an anonymous orchestra during the protests.

But his lyrics are about a different struggle altogether – freeing Hong Kong from Beijing’s control and bringing democracy to the city.

Playing the song in Hong Kong is now all but illegal under the National Security Law.

In September, a harmonica player was arrested for playing the tune to a crowd in memory of Britain’s late Queen Elizabeth II.