China’s recent warning against travel to the Philippines has delivered a sudden, sharp blow to Philippine tourism as visitors are down and AirAsia Zest, a budget carrier, suspended its chartered flights from China to Kalibo, the airport serving the resort island of Boracay.

About 8,000 Chinese tourists canceled their Boracay reservations a day after China issued the travel warning, costing resort operators as much as PHP150-165 million (US$3.5-3.75 million). In total, according to regional Department of Tourism Director Helen J. Catalbas, the Philippines will lose 20,000 hotel bookings between September 13 and March 2015.

“In view of the worsening security situation in the Philippines, the Ministry of Foreign Affairs recently reminded Chinese citizens not to go to the Philippines,” read an unofficial translation of a travel notice posted in Mandarin by the Chinese Foreign Ministry on its website on September 11.

The Chinese ostensibly instituted the travel ban after a series of attacks or threats against Chinese citizens in the Philippines, the most publicized of which was the kidnapping, possibly by Abu Sayyaf militants, of Li Peizhi, a youth working in his family’s business on the island of Mindanao. Another Chinese citizen was shot by gunmen in Bulacan Province. Both incidents remain unresolved.

In addition, police in early September announced they had foiled a bomb plot against Ninoy Aquino International Airport and an attack against the Chinese embassy in Manila. Three suspects were arrested who claimed they were angry at “monopolistic practices of the Filipino-Chinese business community.” Justice Secretary Leila de Lima said added the men “want this administration to espouse a tougher stance in this dispute with China,” a reference to the stand-off with China over territorial claims in the South China Sea

Many observers tie the travel ban to Chinese anger over the Philippines filing a formal arbitration proceeding over Chinese incursions in the disputed Spratly Islands under the UN Convention on the Law of the Sea. The threats to Chinese tourists and businessmen, they say, have hardly risen in number or intensity. The three arrested for threatening to bomb the airport were reportedly teenage amateurs carrying large firecrackers.

In an effort to forestall the damage to tourism interests, the Department of Foreign Affairs told the Chinese embassy in Manila it would take any necessary steps to guard against harm to Chinese tourists and other interests.

“We have also reassured them that the appropriate Philippine authorities are fully investigating the group associated with the three suspects in the NAIA Terminal 3 incident on Sept. 1, 2014,” the foreign affairs department said in a prepared statement, referring to the foiled bombing attempt.

Lingxiao Li, spokesperson for the Chinese embassy, said that under the Vienna Convention on Diplomatic Relations, “the host country is under a special duty to take all appropriate steps to protect the premises of diplomatic missions against any intrusion or damage, and prevent any attack on diplomatic staff.”

China, observers say, has a growing habit of using its overwhelming economic clout in Southeast Asia against those irritated by its political policies, thinly disguising its economic moves with concerns about safety or other apprehensions.

Beijing has also used the tactic against US interests, threatening to replace all Microsoft applications in government computers on security grounds as well as pushing out the Big Three accounting firms and taking other actions after the US charged that Chinese government hackers had hampered US commercial interests.

The Chinese government also threatened Japanese commercial interests in the midst of the squabble between the two countries over the disputed Senkaku (Daioyu) group of islets, cutting off shipments of rare earth elements used in Japanese domestic steel production.

Others say China’s warnings against attacks on its citizens in foreign countries are pretty much a one-way street. In 2013, after a local Japanese government announced plans to buy the Senkakus, the government stood by while anti-Japanese riots destroyed car dealerships and other Japanese businesses in China; Chinese drivers of Japanese cars were even attacked. Similarly, when Malaysian Airlines flight MH370 disappeared, the government stood by while furious relatives of the missing 150-odd Chinese passengers aboard besieged the Malaysian embassy.