Vietnam is accusing a Chinese vessel of attacking and sinking a fishing boat near the disputed Paracel Islands, days after the Chinese government insisted that territories in the South China Sea were not international waters, but belonged to China.

The Associated Press reports that the fishing vessel sank near the Paracel Islands, leaving the ten men aboard to float on lifeboats until help arrived. The ship’s captain, Dang Dung, says the ship was attacked in the middle of the night on September 29 by a Chinese ship. The Chinese vessel rammed itself against the fishing boat and men hopped aboard carrying knives, stealing anything of value– including the catch of the day– before leaving the ship to sink.

“Chinese actions against fishermen from Quang Ngai province have been more aggressive and brutal,” Phan Huy Hoang, president of central Quang Ngai province’s Fisheries Association, told the AP, noting that more than 20 such incidents against Vietnamese fishing vessels have occurred this year.

While there is no indication that the Chinese ship involved in the attack was government-owned, the Chinese Foreign Ministry has used the occasion to assert that the Chinese government will attack and force to flee any ship that enters international waters in the South China Sea that Beijing considers part of China. “Chinese authorities have the rights to take law enforcement measures in accordance with the law on boats that have illegally entered [the South China Sea],” said Chinese Foreign Ministry spokeswoman Hua Chunying.

The Vietnamese Foreign Ministry has issued a response condemning China’s claims to the Vietnamese territory. Spokesperson Le Hai Binh issued a statement “rejecting” the Sansha province of China, which is the name used by Beijing for the international waters including the Spratly and Paracel Islands, both of which are claimed by the Philippines and Vietnam, respectively. “Under any form or for whatever purpose, China’s activities in [Sansha] have no legal foundation and do not change the fact that Hoang Sa belongs to Vietnam,” he said.

Tensions with Vietnam follow a stern warning from Beijing directed that Australia and America for a joint statement in which both nations assured they would treat the South China Sea as international waters, not Chinese territory. “We have a very strong agreement to pursue enhanced naval cooperation, which will include additional combined training and exercises between our two navies,” said Australian Defense Minister Marise Payne this week at a meeting in Boston.

American Secretary of State Ashton Carter added in plain terms: “The United States will fly, sail and operate wherever international law allows… The South China Sea is not and will not be an exception.”

The Chinese Foreign Ministry responded with a statement in which it encouraged the United States to “do more to promote regional peace and stability in the true sense of the words rather than light a fire and add fuel to the flames.” Chinese state media has previously said of the dispute that “war is inevitable” between China and the United States if American ships insist on using the South China Sea as an international trade route.

The Washington Post reports that the United States may act upon Carter’s statement soon, as officials have told the media that “the U.S. Navy may soon receive approval to sail a ship inside the 12-nautical mile (21-kilometer) territorial limit surrounding China’s man-made islands,” according to reports.

In addition to warning the United States to stay out of international waters it claims as its own, Beijing is currently hosting the ASEAN conference, a coalition of Southeast Asian countries, which includes members such as Vietnam and the Philippines. There, Chinese Defense Minister Chang Wanquan suggested the possibility that China could hold joint military drills in the disputed waters with nations claiming them to be international, a proposal that was welcomed by the Philippines.

“That’s a good idea, we welcome that proposal,” a Philippine military commander told Asia One under condition of anonymity.

The Philippine government has been publicly much less conciliatory to China, comparing the leaders in Beijing to Adolf Hitler.