The fishing incident in the Natunas at the weekend, which threatens to escalate into a territorial dispute between Indonesia and China, is down to the conflicting territorial interpretations of the two countries.
While both nations agree that the Natuna Islands, located at the southern edge of the South China Sea, are part of Indonesia, China believes the waters around them fall in what it calls "traditional Chinese fishing grounds". It believes this allows Chinese vessels to fish freely in the area and gives its coast guard the authority to intervene in situations it deems fit.
Indonesia, however, does not recognise the claim, said Indonesian Maritime Affairs and Fisheries Minister Susi Pudjiastuti yesterday. She said Indonesia has made a bilateral agreement on international fishing rights with only Malaysia.
The latest dispute is also separate from the overlapping claims of the South China Sea by Brunei, China, Malaysia, the Philippines, Taiwan and Vietnam.
China has laid claim to most of the South China Sea, occupying more reefs and outcrops in these waters, and building artificial islands as well as airstrips on some of them.
Indonesia, however, is not party to the dispute, said its Foreign Minister Retno Marsudi yesterday after a meeting with China's charge d'affaires for trade, Mr Sun Weide.
Mr Sun was summoned to clarify an incident involving a Chinese coast guard vessel that stopped an Indonesian patrol boat from seizing an illegal fishing boat.
Ms Retno raised Indonesia's objections with Mr Sun, who is China's acting ambassador to Indonesia.
Indonesia protested against the violation by the Chinese coast guard against "Indonesian sovereignty and jurisdiction in the Exclusive Economic Zone (EEZ) and continental shelf", she said.
An EEZ is a United Nations-set limit that gives a state special rights regarding the exploration and use of marine resources, and stretches 200 nautical miles (370km) from its coast.
Ms Retno said the actions of the Chinese vessel also undermined the Indonesian authorities' law enforcement efforts, as well as violated her country's territorial sovereignty.