China’s Under-20s football team stormed off the pitch during a friendly match in Germany after demonstrators unfurled Tibetan flags.

The team – which is coached by former Manchester City defender Sun Jihai - only agreed to continue playing in the televised match against TSV Schott Mainz after the protesters took down the flags.

The incident left football chiefs in China and Germany red-faced as they seek to salvage a series of friendly matches aimed at preparing China’s young footballers for the 2020 Olympics in Japan.

The TSV Schott Mainz game was the first of 16 friendlies the young side is to play against lower clubs in Germany until May - with the next game against FSV Frankfurt on Saturday.

Ronny Zimmermann, vice-president of the German Football Association (DFB), which has organised the matches, said: "We cannot ban the protests, there is the right to freedom of expression here and certain rules apply.

"However, we also want to be good hosts and as a result we are not happy with this incident.”

Sun, who was signed for Man City for £2 million in 2002 and was the first Chinese player to score a Premier League goal, sought to deflect attention from the walkout back towards the football.