Indonesia–Malaysia border Indonesia–Malaysia border The border between the Southeast Asian countries of Indonesia and Malaysia consist of both a land border separating the two countries' territories on the island of Borneo as well as maritime boundaries along the length of the Straits of Malacca, in the South China Sea and in the Celebes Sea. The land boundary has a length of 2,019.5 km and stretches from Tanjung Datu at the northwestern corner of Borneo, through the highlands of the Borneo hinterland, to the Gulf of Sebatik and the Celebes Sea in the eastern side of the island. The boundary separates the Indonesian
Brunei–Malaysia border Petronas Carigali Sdn Bhd and US-based Murphy Sabah Oil Co. Ltd for two areas, which Malaysia calls Block L and Block M, which lie exactly within the area claimed by Brunei as part of its continental shelf/EEZ. Later in March 2003, a Bruneian gunboat was sent to drive away a Murphy drilling ship in the area. The following month, the Malaysian navy sent several gunboats into the disputed area to block the arrival of a Total ship. After a tense stand-off involving a single patrol craft from Brunei, Total backed off and both sides stopped work in the disputed areas.