A huge video panel fell on the stage during a concert by popular Hong Kong boyband Mirror on Thursday, crushing one performer and trapping others, prompting a government investigation and the suspension of future shows.

At least two dancers were injured, with one in serious condition and the other stable, local broadcaster RTHK reported. Three members of the audience were also injured, local media reported, with many fans emotional after the harrowing scenes.

"I am shocked by the incident. I express sympathy to those who were injured and hope that they would recover soon," Hong Kong Chief Executive John Lee said on Friday.

The government would investigate and review safety procedures to protect performers, staff and the public, he said.

Kevin Yeung, the city's culture secretary, said the show would be suspended until the stage structure was safe. The government's leisure bureau had already contacted the concert organiser about other stage incidents in recent days, he said in a statement.

The hugely popular cantopop group was formed in 2018 through a reality television show and had planned a series of 12 shows at Hong Kong's Coliseum, next to the city's Victoria harbour.

More than 13,000 Mirror fans signed an online petition asking the concert organiser to resolve the problems and ensure safety for all performers, according to the petition's website.

MakerVille, the concert organiser which is owned by Hong Kong tycoon Richard Li's PCCW Media Group, said it was thoroughly investigating the cause of the accident.

"We are deeply sorry that the incident caused unease to viewers or others affected."

- Reuters