Movement by the Chinese vessels in Indonesia's Exclusive Economic Zone concerned the Indonesian Military or TNI. The trespassing has caused Jakarta to deploy more forces into the region. The TNI increased the surveillance in the South China Sea to ensure that the trespassing wouldn't happen again. The Chinese vessels including a coast guard boat entered the territory which is considered as an EEZ and called Natuna Sea.
The self-imposed nine-dash line by the Chinese in the South China Sea has been a cause of distress between the littoral states since the past few years.
TNI spokesman Maj Gen Sisriadi said on Friday that they are not only deploying ships but fighter jets as well, making the military go on alert for any oncoming clash with the Chinese fleet. The TNI will also activate Maritime Information Center to detect any movement by vessels violating the borders. The Indonesian Foreign Ministry believes that the Chinese violated the International Law and the maritime boundaries by entering their EEZ.
Beijing is a part of the United Nations Convention to the Law of the Seas
A Foreign Ministry spokesman said that China has the right to sail its ships near the Natuna Islands. The hardened stance came after Indonesia protested about Chinese boats including coast guard ships entering the region. Beijing thwarted the Indonesian statement about Chinese vessels sailing in their EEZ had no legal basis.
Geng Shuang, the Foreign Ministry spokesman said that the actions by China comply with International Law and UNCLOS ( UN Convention on the Law of the Sea). In 2016, the Philipines filed a complaint against China after Beijing's assertive behaviour in the South China Sea. The Permanent Court of Arbitration said that there was no legal basis to the claims of historical rights to the sea. Since then, China has built several man-made islands and other projects to grow its assertion in the South China Sea.
China is a part of the International Convention to the Law of the Seas which addresses various concerns of the nations about maritime territoriality.