Lamine Yamal waves Palestinian flag at Barcelona open-top bus title parade

Lamine Yamal waved a Palestinian flag at the title parade (AP)

Barcelona winger Lamine Yamal waved a Palestinian flag during an open-top bus parade on Monday as the team celebrated winning the Spanish title.

The 18-year-old star, who is already widely regarded as one of the best footballers on the planet, held the flag as the team bus drove through the streets of Barcelona. He also posted pictures of him holding it on his Instagram account.

On Tuesday, Barcelona head coach Hansi Flick was questioned about Yamal's decision to wave the flag.

"This I don’t normally like," Flick said at a news conference. "I spoke with him. I said if he wants this, it is his decision. He is old enough. He’s 18 years old."

Hansi Flick said it was Yamal's decision to wave the Palestinian flag (AP)

There has been a global backlash against Israel over the humanitarian toll of the war in Gaza, which has spread to sport and culture. Protests have been seen in sports such as soccer, cycling and basketball.

By holding the flag, Lamal appeared to indicate his support for Palestinians as an estimated 750,000 people took to the streets to celebrate Barcelona's La Liga title triumph, which was confirmed following their 2-0 El Clasico win against on Sunday.