The civil aviation authority has called on consumers to keep a rational attitude when defending their rights after two incidents in three days of dissatisfied passengers entering airport taxiways to seek compensation for flight delays.

As concerns arose that similar incidents might take place, the Civil Aviation Administration of China responded on Sunday, saying that it is investigating the causes of the two incidents.

It also issued an urgent notice demanding airports and airlines to do their best to serve passengers when flights are delayed.

"Passengers entering the flight control area without permission not only violate laws, but also put their own safety in danger ... We hope consumers can safeguard their rights in a rational manner and in line with the laws," CAAC said in a statement.

On Friday, an unknown number of passengers ran into the taxiway of Guangzhou Baiyun International Airport because their flight, carried by Hainan Airlines and scheduled to depart at noon, was delayed four hours due to thunderstorms.

According to video clips uploaded by a netizen, dozens of angry passengers gathered at the boarding gate and argued with police officers and airport staff. Some of them rushed to the taxiway, but were stopped by a line of police officers.

A netizen, "Miss Xiaobaiyang", said on Sina Weibo that a male passenger even took off his shirt and lay down on the ground to stop a van that carried VIP passengers.

Some netizens said these passengers may have been motivated by a similar incident on Wednesday at Shanghai Pudong International Airport, where about 20 dissatisfied passengers ran to the taxiway demanding compensation because their flight was delayed 20 hours due to bad weather.

Their sudden appearance forced an Etihad Airways flight about 200 meters from the passengers to stop on the taxiway. Entering an airport tarmac without permission is illegal and punishable by a minimum fine up to 200 yuan ($32) or as much as five years in prison.

The dispute was settled after each passenger received 1,000 yuan - double the normal standard - from the delayed flight's carrier, Shenzhen Airlines. None of the passengers was fined.

Shanghai police said some passengers were punished the next day according to laws, but did not provide further details.

Industry insiders said entering an airport taxiway without permission is disruptive and extremely dangerous.

"The engines of a taxiing plane are like huge vacuums. Things in front of engines could be sucked in and killed. A sparrow sucked in by an engine could turn out be a mess of blood plasma, and so will a human being. The engine will also be shattered," said Mao Senlin, a retired pilot.

But many netizens sympathized with the passengers, saying that flight delays have long been a problem.

Passengers stranded in Guangzhou Baiyun International Airport said the carrier gave no explanations for the delay. At Shanghai Pudong airport, passengers said the flight was delayed for 20 hours, and they slept only for two hours.

Zhang Qihuai, a lawyer specializing in the civil aviation sector, said airlines cannot be tough and say no to passengers' compensation requests.

"Airlines have to regulate themselves and make sure everything they've done is unquestionable first, otherwise they cannot justify themselves when punishing troublemakers ... They have a lot to do to improve their service," he said.

Industry insiders believe that the reason some passengers seek a large amount of compensation is because there is no unified standard.

The CAAC issued in 2004 a guidance that said airlines should compensate passengers if flights are delayed for more than four hours, but did not give unified compensation standards. Most airlines set their own compensation standards, which vary in size.

The measures being taken by passengers are getting more extreme, and some requests are not justified, said Gu Shengqin with the Chinese Society of Aeronautics and Astronautics.