China, on the other hand, claims that the Kway Fey 10078 was fishing in the nation's historically traditional fishing grounds when it was harassed by an Indonesian patrol vessel, and therefore send two armed coast guard ships to assist the Kway Fey. Reportedly, one of the Chinese coast guard ships deliberately collided with the Indonesian patrol vessel that was towing the Chinese fishing boat to the Natuna Islands off the northwest coast of Kalimantan for further investigation. To avoid further escalation, the Indonesian patrol vessel let go of the Kway Fey which was then taken back to Chinese waters. However, the Chinese fishermen remain detained by Indonesian authorities. China immediately requested Indonesian authorities to release the Chinese fishermen and ensure their safety.

The case caused an uproar on both sides. However, Indonesian Foreign Minister Retno Marsudi emphasized that Indonesia wants to maintain good relations with China. Both countries are important trading partners while China is also among the biggest foreign direct investors in Indonesia. Marsudi sent an official letter of protest about the confrontation in the South China Sea to the Chinese Embassy in Jakarta. This document mentions three matters. Firstly, China's violations of Indonesia’s sovereignty and jurisdiction on the Exclusive Economic Zone at the Natuna Islands. Secondly, Chinese authorities' actions to combat law enforcement measures taken by Indonesian authorities. And thirdly, violations of Indonesia’s sovereignty over its sea territory.

Since President Joko Widodo took the presidential driver's seat in late-2014, Indonesia has taken a more assertive approach in terms of protecting its sea territory. Over the past months dozens of foreign vessels caught fishing illegally in Indonesian waters have been blown up (after crew members were arrested). As China's military presence in the disputed South China Sea area has grown, Indonesia also also started to deploy warships in the waters around the Natuna Islands. The case seems to show that Indonesia has now toughened up its stance on territorial disputes in the South China Sea. Previously the country remained rather silent and avoided becoming caught up in disputes between China with the Philippines and Vietnam. It preferred the position as mediator.

China claims possession of over 80 percent of the South China Sea, one of the busiest waterways on earth. These claims are based on China's so-called nine dash line. The international community, however, does not recognize this nine dash line. The 1982 United Nations Convention on the Law of the Sea (UNCLOS), in which Indonesia and China are both participants, also does not recognize "historically traditional fishing grounds" as claimed by China. China has been in territorial disputes with several of the 10-nation Association of Southeast Asian Nations (ASEAN) primarily due to China's land reclamation projects in the disputed areas, and the stationing of China's military.

In March 2013 a similar incident took place. After a Chinese fishing boat was caught fishing illegally in Indonesian waters near the Natuna Islands, the boat was confiscated and its crew was arrested. However, an armed Chinese vessel arrived and demanded the immediate release of the crew and boat. Being outgunned and under severe pressure the Indonesian vessel then complied with Chinese demands. This incident has seldom been spoken of and that makes it rather different from the current illegal fishing case. In the current case Indonesian authorities have reacted strongly in their statements.