BEIJING (REUTERS) - China's aviation regulator said it will withhold approvals of new air routes, chartered services and additional flights at the Shenzhen Baoan International Airport for the rest of the year due to its mishandling of major flight delays.

The delays at the second-tier Shenzhen airport since the second half of 2014 have led to several serious incidents, the Civil Aviation Administration of China (CAAC) said in a rare rebuke that was issued late on Monday.

Delays at the airport, which is operated by Shenzhen Airport Co, have triggered four major incidents in May alone, the CAAC said.

Passengers for a delayed flight, operated by Shenzhen Airlines, arrived on the tarmac in front of the plane before the crew got there, while passengers on a China United Airlines flight opened an emergency door after waiting on board for four hours on another delayed flight.

An executive with Shenzhen Airport's board secretary office declined to comment.

China's aviation sector has grown rapidly in recent years, driven by demand from the country's increasingly wealthy middle class. Outbound passenger volumes rose 39 per cent year-on-year in January-May this year after topping 100 million for the first time in 2014.

But its airports have been plagued by delays, and incidents involving unruly passengers are on the rise.

The country will invest 500 billion yuan (S$111 billion) in 193 major domestic aviation projects this year, the CAAC has said, in order to alleviate the congestion.

Shenzhen Airport's shares were up 6.2 per cent on Tuesday afternoon.