China and Singapore have joined Japan and South Korea in restricting flights by Thailand's airlines as the kingdom scrambles to address "significant safety concerns" by the U.N.'s International Civil Aviation Organization (ICAO).

The January audit in Thailand "revealed some safety concerns, primarily relating to air operator certification procedures," said Anthony Philbin, communications chief for the ICAO Secretary General in Montreal in an e-mailed response to a VOA query. "We can’t discuss any further details in light of the agreement in place between the Organization and its Member States governing the conduct and reporting of ICAO universal safety oversight audit results."

Thailand worries about effect on tourism

Travel industry officials in Thailand worry the perception that the country's airlines are now unsafe could further hurt tourism. The crucial sector for the Thai economy, employing millions of people, has been beset over the past 18 months by concerns about tourists' safety and political unrest.

Seeking to reassure the flying public, the director-general of Thailand's department of civil aviation, Somchai Piputvat, on Tuesday explained that the shortcomings in the ICAO audit involve regulatory issues, not safety failings by the airlines.

"It will be safe to fly the carriers based in Thailand," Somchai told VOA.

But industry sources say the most serious concerns involve low-cost carriers failing to meet safety regulations, including certifications for air operations and the transportation of hazardous goods.

Thailand to address concerns

The director-general explained that two panels are to urgently be established: one to reform the civil aviation department and the other to mitigate the effects of the ICAO downgrading Thailand's safety rating.

The civil aviation department has complained for years to politicians that it does not have enough officers to keep up with the large increase in the number of airlines that have been created in Thailand in recent years. It has announced additional training will be provided to its staff and airline inspections will be increased.

"This is our mistake and we have to concede that we violated the rules and we must find ways to address the problem," said prime minister Prayuth Chan-ocha, who seized power in a military coup last May.

The former army chief also stated he would use powers under Section 44 of the interim charter to rectify the problems of Thailand's airlines.

Section 44 effectively allows the junta boss to issue any orders he deems appropriate without judicial or other oversight.

The transport ministry met with representatives of the country's airlines on Tuesday to discuss the matter.

Other nations react to questions about Thailand's airlines

The ICAO negative review has prompted several countries to begin blocking new and charter flights from Thailand. There is concern more countries, including the United States, will take similar action, especially if the ICAO downgrades Thailand from Category 1 to Category 2.

A U.S. government source - who is not authorized to speak on the record - explained the ICAO report would probably trigger an audit of Thailand's aviation sector by the Federal Aviation Administration. He called the ICAO audit results a "real red flag for the FAA."

Japan and South Korea do not conduct their own assessments and usually rely on ICAO findings to take action.

Japan's Civil Aviation Bureau said that for now, no new charter flights operated by airlines registered in Thailand would be allowed to fly to Japanese airports because of concerns the carriers may not meet international safety standards.

Thai officials blame past leaders

Thailand government officials are blaming politicians of previous administrations for not concentrating on the problem.

"The ICAO has warned us since 2005 about our aviation management and asked us to improve our systems," Prajin said.

The ICAO has rejected the civil aviation department's enhancement plan, submitted March 2, reportedly because it proposed a two-year period to fix problems. Thailand plans to submit, on April 7, a revised proposal promising to solve the issues within eight months.

Critics have said Thailand's civil aviation sector suffers from frequent changes of government, corruption, complacency and incompetence.

On professional pilots' forums on the Internet, industry workers allege Thai government inspectors were bribed with cash and massages to favorably sign off on paperwork.

Somchai told VOA that no such allegations had yet come to his attention.

"It's the goal of the government and my policy that no corruption will occur in Thailand or in the department of civil aviation. I will look for this very carefully and immediately," he said.

US will scrutinize Thai air industry

The FAA is likely to conduct its own aviation safety assessment of Thailand that would three critical areas: airworthiness of aircraft, airman licensing and operator requirements, said a U.S. government official familiar with the procedures.

An FAA downgrade for Thailand would mean, among other things, a suspension of code share operations where a Thai carrier is the operating carrier.

Effects of negative airline report already being felt

Currently operated flights have not been affected by the ICAO audit. But the loss of new and charter flights during the April-May high tourist season will affect more than 150,000 passengers, according to the Bangkok Post.

Travel operators said this has caused the price of some package tours during the Songkran holiday to nearly double.

The Association of Thai Travel Agents said the restrictions imposed by Japan could result in a drop of 2,000 Japanese visitors to Thailand in April.

Other than the kingdom's flag carrier, Thai Airways International, the ICAO safety warning is also affecting low-cost carriers Thai Air Asia X, NokScoot, Orient Thai, Skyview and Asia Atlantic airlines.

It is not convenient "to give an interview or comment on this matter at this moment," said Nuttavika Tamthai, international corporate communications chief for Thai Airways.

The state-controlled airline on Monday announced that after posting annual losses in the past two years it expects a significant loss in 2015 before returning to profitability next year, partly by selling aircraft and dropping routes.