Russian twin sisters competing in the Eurovision Song Contest were booed by the crowd Tuesday after advancing to the finals of the annual song competition.

The Tolmachevy Sisters, who are representing Russia, advanced to the finals with nine other countries, including Ukraine.

The semi-final round in Copenhagen appeared to turn political for a moment, when the crowd of about 10,000 people started to boo the 17-year-old sisters after it was announced that they would be proceeding to the next round.

The sisters' performance saw them take the stage decked out in flowing white gowns and armed with glass cylinders. Together, they sang their track "Shine" amid a flurry of bright lights and smoke.

Meanwhile, Mariya Yaremchuk represented Ukraine with her song "Tick-Tock." The brunette singer controlled the stage with a strong performance, which included interactions with a man running in a giant hamster wheel behind her.

Yaremchuk later told reporters that she was singing for all Ukrainians.

"My main message is that time is now, and there are more important things than politics. Eurovision is a better way to unite people than politics," she said.

Other finalists include Armenia's Aram MP3, who delivered a powerful solo performance – without any props -- of his song "Not Alone." 

Icelandic band Pollaponk rocked the stage wearing bowties and colourful suits for their song "No Prejudice."

The 10 countries that advanced Tuesday will join another 10 countries which will be chosen in a second semi-final round on Thursday. The 20 finalists, along with Germany, France, Italy, Spain, the U.K. and Denmark, will compete in the grand final on Saturday.

The Eurovision Song Contest is held annually among the member countries of the European Broadcasting Union.

The contest sees each member country submit a song that will be performed on live TV and radio. Residents of each country must then vote for other countries' songs, and points are awarded to the songs based on how many votes they get.

While there is no cash prize for winning the contest, past competitors have gone on to have highly successful careers. Abba, Julio Iglesias and Celine Dion have all competed in the contest in the past.

The competition, which started in 1956, is one of the longest running TV programs in the world, and garners hundreds of millions of viewers each year.