China slammed Indonesia on Sunday for “harassment” after its navy detained a Chinese boat and its seven crew, accusing them of fishing illegally in Indonesian waters of the South China Sea. The fishermen were intercepted near the Natuna islands on Friday, Indonesia’s navy spokesman said. This is at least the third such incident since March. Last month, Indonesia’s navy fired shots at a Chinese trawler when it refused to stop fishing in Indonesian waters, and then seized the vessel and its eight crew. Indonesian navy fires shots, seizes Chinese fishing boat near disputed South China Sea In response to the latest incident, China’s Foreign Ministry Spokesperson Hua Chunying said China strongly protested against Indonesia’s actions and condemned the detention of the crew. Hua said the fishermen were “harassed” by and shot at by the Indonesian navy during their “regular fishing operation”, and that China had immediately dispatched coastguard vessels nearby to protect the fishing boat and the crew. “The Indonesian naval warship has abused their force, to harass and shoot at the Chinese fishing boat and has threatened the safety and property of the Chinese fishermen,” she said. “This has seriously violated the United Nations Convention on the Law of the Sea [UNCLOS] and the Declaration on the Conduct of Parties in the South China Sea,” she said. One fisherman was injured during the incident, and was transported to nearby Hainan province for treatment, Hua added. The UNCLOS, a treaty which both China and Indonesia are signatories, provides guidelines for how nations use the world’s seas and their natural resources. Indonesia blows up illegal toothfish ship sought by Interpol The Indonesian warship KRI Imam Bonjol-383 responded to a report from maritime air surveillance officials that 12 foreign fishing boats were illegally working in the Natuna Sea, First Admiral Edi Sucipto said. Following warning shots, one of the fishing boats stopped and was found to be a Chinese boat with one women and six men as crew, all of whom were Chinese citizens, he said. Chinese fishermen has become increasingly active in international waters after the severe depletion of fish resources caused by overfishing and pollution in the waters near home. But their illegal fishing activities have often resulted in arrests, leading to diplomatic tension between China and its neighbours. Last week, South Korean coastguard commandos seized two Chinese fishing boats operating illegally in the neutral waters of the Han River estuary between the two Koreas. The development comes after Seoul reported a growing number of Chinese fishing boats trespassing into the military buffer zone as blue crab season went into full swing. The intrusions have fuelled security concerns over the closely monitored frontline region, South Koreas’ Yonhap News Agency reported.