Manchester United's showpiece pre-season derby against Manchester City was cancelled just hours before kick-off Monday after recent "extreme" rain made the Beijing pitch unsafe.

"The rain has made it totally unsafe to play on this pitch," said Manchester City CEO Ferran Soriano in a statement.

Organisers of the International Challenge Cup tournament, which also features Borussia Dortmund, confirmed the match had been called off on grounds of player safety.

"The conditions experienced in Beijing on July 19 and July 20 were reported as being some of the most extreme weather conditions the capital of China has experienced in recent history," said a statement from the organisers.

"The committee and both teams make the decision together in the interest of player safety."

Both managers, Jose Mourinho of United and Pep Guardiola of City, had told reporters Sunday they were worried about the state of the pitch at the 2008 Olympic venue following flooding in and around the Chinese capital.

Mourinho had hinted 24 hours earlier that the match might be called off after training was switched from the Bird's Nest to another ground.

"The pitch and the conditions of my players are more important than results in pre-season," said Mourinho Sunday.

"It is almost the end and we can go home and train in conditions where the players are safe."

Guardiola was similarly blunt when asked what he wanted from the match. "No injuries," he replied.

Manchester United vice-chairman Ed Woodward said Monday he was sad to have the club's Chinese fans lose a rare opportunity to see their heroes in the flesh.

"It's extremely disappointing not to be able to play the game in this amazing stadium but the recent torrential rain would have caused problems anywhere in the world," Woodward said in a statement.

"We know our fans in China will, like the players and staff, be saddened by the cancellation of the match but I am sure they appreciate that the player safety has to be the top priority. I am sure we will return to the Bird's Nest in the future."

Around 50,000 tickets had been sold at up to $200 for the clash and organisers said they would all be refunded at huge expense.

"We thank... the tens of thousands of fans who committed to purchasing tickets," said International Champions Cup spokesman Patrick Murphy. "An appropriate refund policy will be put in place."

It was the final indignity to follow a chaotic weekend in China for Mourinho's new club after losing 4-1 to Borussia Dortmund Friday night in Shanghai in their opening, and now only, China tour match.

Half of United's squad were on a plane which had to make a forced landing between Shanghai and Beijing on Saturday because of a violent storm in the capital.

Striker Memphis Depay tweeted a video of himself outside the plane in Tianjin, saying they were "lost in China". The players eventually made it to the team hotel in Beijing at 1:00 am.

Meanwhile Sunday's makeshift training venue struggled to cope with the invasion of hundreds of media to cover the teams' every move.

Mourinho refused to attend a news conference in an overcrowded and stiflingly hot press room, instead holding a bizarre press chat amid a scrum on the running track where he struggled to be heard.

The cancellation means that fans will now have to wait until the English Premier League derby on September 10 for the bitter rivalry between Mourinho and Guardiola to be renewed.

United will now leave Beijing to return to Manchester late on Monday night as originally planned, while City will fly to the southern city of Shenzhen on Tuesday for Thursday's game against Borussia Dortmund.