Tourist and Sports Minister Suvit Yodmani said he was monitoring the search for the killer. He called on the Tourist Police to wrap up the case as soon as possible.

Suvit stressed that the incident had damaged the tourism image of Pattaya.

For years, Russians have been the biggest market for Pattaya businesses. They spend more and stay longer that tourists from other nations. Russian tourists take charter flights from Moscow and other major cities directly to Pattaya.

Following the murders, Suvit said that the United Kingdom, Australia and Canada had responded by issuing travel warnings for Thailand.

"Foreign governments have the right to warn their citizens about the risk of travel in dangerous cities. Australia faced a major controversy once, when many tourists were killed overseas in the absence of travel warnings," said Suvit, apparently alluding to the 2002 Bali bombings in Indonesia, when 88 Australian nationals died.

However, there is no report of tour cancellations from Russia.

Association of Domestic Travel president Charoen Wangananont said the killing of the two Russians had already damaged the tourism industry, especially because the victims were young women.

Besides calling on the authorities to search for the suspect, the association urged the government to run more promotional campaigns to demonstrate that Thailand is essentially a safe place to visit.