China is angry after a violent hostage drama in the Philippines killed eight tourists from Hong Kong, and the Southeast Asian nation can do little to soothe the powerhouse, as a raft of visitor cancellations has hit the country's tourism industry. Tens of thousands of people have marched in Hong Kong to denounce the Philippines and thousands of Chinese tourists canceled flight and hotel bookings. Two Chinese recipients of Asia's most prestigious award failed to show up for the Manila ceremony. President Benigno Aquino III has asked for China's forgiveness while vowing “someone will pay” for the embarrassing official handling of the 11-hour hostage-taking Aug. 23 that unfolded live on television. Eight tourists were killed before police snipers took down the gunman, a dismissed policeman demanding his job back. Survivors said he became enraged after watching police handcuff his brother for interfering in the negotiations. On Tuesday, Aquino promised an investigation that would be “unassailable” in under two weeks. China is the country's third largest trading partner after the US and Japan – two-way trade reached $6.7 billion last year – and its fury is taking its toll. Flag carrier Philippine Airlines and budget airline Cebu Pacific reported more than 1,000 cancelations from the Chinese territory of Hong Kong alone. “It created a domino effect,” said PAL spokeswoman Cielo Villaluna. “We are hoping that the situation will be temporary.” In the prime beach resort of Boracay, hundreds of Chinese tourists scrapped their bookings, said regional tourism director Edwin Trompeta. Losses could top half a million dollars, he said. Emotions ran high in Hong Kong on Sunday when 80,000 people marched to show “the anger and unity of the Hong Kong people,” lawmaker Cheung Man-kwong said. Hong Kongers blasted Manila police for what they called an amateurish rescue attempt. In another setback, two of three Chinese recipients of the Ramon Magsaysay Awards, named after a popular Philippine president and considered an Asian Nobel Prize, failed to show up in the Philippines for a gala ceremony scheduled for Tuesday in Manila. “We respect the sensitivities of the Chinese. We understand we are now in a situation wherein they are demanding some measure of justice,” presidential spokesman Edwin Lacierda said. But Filipino political analyst Ramon Casiple said both sides should be careful not to further escalate tensions. “It's not in China's long-term interest to fight the Philippines and the vice versa, but the danger of an escalation is still there,” Casiple told The Associated Press. “The Philippines should avoid provocative actions and ensure a transparent investigation that will satisfy this call for justice.”