SYDNEY, Oct. 10 (Xinhua) -- Thousands gathered at Australia's Sydney Opera House on Tuesday night, when protesters shined torches and lasers onto the structure's iconic sails-like facade to disrupt a six-minute light show promoting the country's richest horse race, local media reported.

The controversial advertising for the race, which boasts 13 million Australian dollars (9.25 million U.S. dollars) in prize money, has seen groups ranging from politicians to media personalities debating whether a sport centering on gambling should be promoted on the heritage-listed venue.

The opera house has been used to project colors and images to mark major public events such as holidays and festivals.

Up to 3,000 people crowded the city's area on Tuesday night, while an online petition to its New South Wales state government against using the structure as a "promotional billboard" garnered more than 200,000 signatures, reported the Nine News channel.

State Premier Gladys Berejiklian has not ruled out using the venue to promote other events and told media she did not want the state to "fall behind" in tourism, according to the news channel.

"I hear what people have said about what they want to see the Opera House used for and what they don't want to see it used for," the channel quoted her as saying.

"As premier of NSW I have to balance those decisions ... These are issues that we take on board."