“The tourism sector may suffer a huge negative impact if many countries issue travel advisories in relation to the warnings of bomb threats raised by the Thai police,” Thai Travel Agents Association president Suparerk Soorangura said.

Many foreign travel agencies and hotels are including Thailand in packages for the upcoming high season, so it is too soon to judge the number of advance bookings or cancellations, he said. If the government is unable to control speculation or ensure confidence in the international market, many tourists will shift their trips to other countries such as Vietnam, Indonesia or the Philippines, he added.

“Our high-season period will be badly affected if tourists do not make bookings,” Suparerk said.

Supawan Thanomkiatphum, president of the Thai Hotels Association, said security had been tightened at many hotels and public areas as a precaution.

Airports of Thailand earlier announced tighter security measures at the country’s six international airports, while the public transportation system is also implementing security measures.

Meanwhile, national police chief Pol General Chakthip Chaijinda affirmed that information obtained by the intelligence services about plots for three bomb attacks in Bangkok and the vicinity between October 25 and 30 was in line with reports from their international counterparts.

He said police investigators, led by his deputy for national security, Pol General Srivara Ransibrahmanakul, were looking into the leads but he declined to say if suspects detained after Tuesday’s raids were linked to the alleged plots. He added that the end of October coincided with several key dates, including the anniversary of the founding of a southern insurgent group.

Army chief General Chalermchai Sittisart has refused to say if the threat of bomb attacks in Bangkok might be linked to the unrest in the deep South, although he did say that cars stolen in the region might be used in the attacks. He added that attacks would not affect the ongoing peace dialogue regarding the Southern unrest.

Chalermchai said the Peace and Order Maintaining Command had been instructed to help police to monitor communities and public areas, including malls, so people should not panic but be vigilant for suspicious items. He added that security forces were investigating the latest warnings.