Thai security agencies are on alert after receiving a warning from Moscow's top intelligence agency that a group of Islamic State in Iraq and Syria (ISIS) militants has entered Thailand and could be planning to target Russians here.
The circular from Thailand's Special Branch to its offices, with a Nov 27 stamp, was leaked to the media on Thursday night and confirmed authentic yesterday morning by police. It said Moscow's Federal Security Service had told Thai police that 10 Syrian militants from ISIS had entered the country between Oct 15 and Oct 31 to target Russian interests.
With 1.6 million arrivals last year, Russians account for a big chunk of Thailand's foreign tourist market, the highest number from any European country. There are enclaves in Pattaya, a favourite destination - where shop, hotel and restaurant fronts and menus are in Russian.
"They (the Syrians) travelled separately," the letter said. "Four went to Pattaya, two to Phuket, two to Bangkok and the other two to (an) unknown location." The letter was marked "secret" and "urgent".
The Thai authorities seemed to have been taken off guard by the leak. At a press conference yesterday, deputy police spokesman, Colonel Songpol Wattanachai, downplayed the letter, saying: "So far, it is only intelligence news that still needs to be proved... we have no proof if they are here for real or not."
But he added: "Please be confident… we won't disregard the intelligence."
Russia has, since September, joined in the conflict in Syria in support of President Bashar al-Assad, bombing ISIS areas, but also targeting forces opposed to Mr Assad.
On Oct 31, a bomb apparently planted by ISIS exploded on a Russian airliner which crashed in Egypt's Sinai desert, killing all 224 people on board, mostly Russian holidaymakers.
On Nov 13, ISIS militants attacked crowds in Paris, killing 130 people, raising global alarm at their ability to strike in foreign countries and increasing concern that ISIS may ally with militants in South-east Asia.
Thailand offers a myriad of soft targets and has long been fortunate to escape international terrorism, security experts say - until the bomb blast in Bangkok on Aug 17 which killed 20, mostly foreigners of Chinese origin. Uighur militants active in smuggling Uighurs out of China through Thailand have been accused of the bombing; two are in custody in Thailand.
The bomb changed the equation for Thailand, analysts say. "Terrorism in Thailand is no longer an abstract issue. We are now looking at a very new world," Mr Anthony Davis, a security analyst with IHS Jane's, said at a discussion on the ISIS threat in South-east Asia, at the Foreign Correspondents Club of Thailand on Thursday.
Thailand was vulnerable, he said, offering easy targets in numbers of foreigners from around the world, a significant level of official corruption and significant criminal elements among the foreigners.
Russian intelligence information must be taken seriously, he said in an interview. "The bottom line is, it is a worry. The Russians would not have panicked over nothing."
Separately, a security and intelligence analyst who asked not to be named told The Straits Times he was "not surprised" by the news.
He said: "There has been a lot of tightening up since the Aug 17 blast, but Thailand remains porous... And while the Thais are very good at internal policing, they are weak at understanding wider strategic issues."