Here is a simple diagram of the marine zones off a coastal country, indicated which ones are exclusive and which ones can be utilised, for various activities, by foreign ships.
Schematic map of maritime zones (aerial view).
Explanations of what foreign ships are permitted by UNCLOS to do, in those waters, is also explained.
Territorial waters - Wikipedia
Let's be quite sure what the "foreign" ships have been doing there, prior to accusations of "intrusions", "patrolling around" or "still in the area" as reported by the ameristani regime funded source, of MK's post.
Let's not also not forget the ASEAN + 3 organisation, is currently drawing up "acceptable" management procedures. Which they suggest will be completed this year. One hopes they complete the negotiations prior to any non ASEAN + 3 countries creating any further disturbances.