A Vietnamese fishing crew say a Chinese coast guard vessel rammed their boat this summer in the South China Sea. During the attack, the Chinese crew allegedly beat the Vietnamese fishermen and forced them to sign a statement handing over $20,000 worth of fish and equipment, Bloomberg reported on Tuesday.

The incident occurred near Vietnam’s Paracel Islands, a disputed archipelago in the South China Sea’s north claimed by China.

On the morning of June 10, “a Chinese Coast Guard patrol vessel and a speedboat chased, rammed, and damaged” a Vietnamese fishing boat with a crew of 15 from Ly Son island, Vietnamese online newspaper VnExpress reported on June 14.

“During the attack, personnel from the Chinese patrol vessel … attacked the fishermen and forced them to sign off on a statement,” the newspaper relayed. According to Bloomberg’s account, the Chinese coast guard members “beat” the Vietnamese fishermen and “forced them to fingerprint a statement” before seizing the boat’s fish and equipment.

The Chinese “took away two GPS positioning machines and a fishing sonar, a coracle [small boat], ropes, and one ton of seafood after damaging the fishing boat,” according to VnExpress. The Vietnamese fishing boat suffered $21,500 worth in damage and losses.

“With the vessel damaged and equipment stolen, the crew could not continue and returned to shore on Friday [June 12, two days after the attack] and reported to Quang Ngai authorities,” according to the newspaper. The boat hailed from Ly Son island, which is considered part of nearby Quang Ngai province.

On June 13, several Vietnamese government bodies – including the Ministry of Foreign Affairs and the Vietnam Fisheries Society – sent a joint letter to Vietnam’s Government Office condemning the incident and China’s “inhumane actions, which threatened the life and damaged the properties of Vietnamese fishermen.”

On the same day as the attack, “the Consular Department at Vietnam’s Foreign Affairs Ministry and Vietnam’s Embassy in Beijing had discussed the matter with China, asserting Vietnam’s sovereignty rights over Hoang Sa [the Paracel Islands],” according to VnExpress. “The agencies demanded that China investigate and verify the incident and inform Vietnam with the results,” so that both sides could take further necessary actions.

“Such actions by China have occurred many times and are increasing relentlessly, causing insecurity and discontent among Vietnam’s fishermen, reducing Vietnam’s fishing production, causing serious economic losses to fishermen, infringing on Vietnam’s sovereignty and violating Vietnamese and international laws,” the Vietnam Fisheries Society wrote in its statement on the matter.

A Chinese ship hit and sunk a Vietnamese fishing vessel and detained its crew near the Paracel Islands in April. In the months since then, Beijing has ignored international calls to halt its aggressive behavior in the South China Sea, which it illegally claims almost in its entirety. Instead, it has continued to bully Vietnam and other Southeast Asian nations surrounding the sea out of exploring natural resources within their own exclusive economic zones.

The South China Sea is home to some of the richest fish stocks in the world and boasts an abundance of natural energy sources; it is also located along global trade routes, making it a highly coveted and contested body of water. In addition to China and Vietnam, portions of the sea are claimed by the Philippines, Malaysia, Indonesia, Brunei, and Taiwan.

While most Southeast Asian nations generally try to protect their sovereign territory within the sea as designated by international law, China encroaches upon other nations’ exclusive economic zones, undermining their territory rights.