Robbie Williams shows middle finger on TV during World Cup opening ceremony

Russia & Saudi Arabia fans arrive at World Cup opener (0:29)

Russia and Saudi Arabia fans are out in full force ahead of the 2018 World Cup opener. (0:29)

English singer Robbie Williams began the World Cup by displaying an obscene gesture toward the camera during the opening ceremony.

The pop star was singing at the Luzhniki Stadium in Moscow before the first game of the tournament when he showed his middle finger to the TV cameras, with hundreds of millions of viewers expected to tune in.

Williams had been criticised in both Russia and England before the event for agreeing to participate in the ceremony.

The 44-year-old had said he was told not to use his song "Party Like a Russian," which pro-Kremlin media outlets suggested mocked Russian oligarchs, while critics in England objected to Williams performing at such a major event for a country that has been accused of human rights abuses.

Just before making the gesture, Williams also added the line "I did this for free" to his lyrics. English media speculated that he was hitting back at human rights campaigner Bill Browder, who had accused him of "selling your soul to a dictator."

The incident led American broadcaster Fox to issue a statement apologizing for showing the gesture.

"The 2018 FIFA World Cup opening ceremony was a newsworthy event produced by a third party and carried live on Fox," the statement said. "As it was broadcast live, we did not know what would happen during Robbie Williams' performance and we apologize."

The 15-minute show, produced by Russia's state Channel One, broke from World Cup tradition, focusing on musical acts, including a performance of Pyotr Tchaikovsky in front of full stands at the capital's main stadium.

Iker Casillas and Russian supermodel and philanthropist Natalia Vodianova brought the World Cup trophy onto the pitch in a Louis Vuitton travel case.

Williams performed hits "Let Me Entertain You" and "Rock DJ" -- but not his controversial "Party Like a Russian -- while accompanied by dancers and freestylers. He was joined in a duet by Garifullina, a soloist from the Vienna State Opera who entered the pitch on a firebird, singing Williams' hit song "Angels."

The opening ceremony was followed by the first match between Russia and Saudi Arabia, with the hosts winning 5-0 in front of on-looking Russian President Vladimir Putin.

Information from Reuters was used in this report.