JAKARTA (AFP) — Indonesia has driven a Chinese coast guard ship from contested waters in the South China Sea for the third time this week, its maritime security agency said Saturday.

It is the latest move by a Southeast Asian nation against Beijing’s actions in the strategic waterway, which it claims almost in full.

Chinese vessels have occasionally entered Indonesia-claimed areas of the North Natuna Sea at the southern edge of the South China Sea, drawing protests from Jakarta.

“The China Coast Guard-5402 (CCG-5402) re-entered the Indonesian jurisdiction on Friday,” Indonesia’s Maritime Security Agency said in a statement Saturday.

The same ship first entered the disputed waters on Monday and again on Wednesday, with Indonesian patrol ships driving it away both times, the agency said.

It added that the Chinese vessel on Monday had disrupted a survey being conducted by state-owned oil company Pertamina, and that when contacted by an Indonesian ship, the Chinese coast guard said the area was part of Beijing’s jurisdiction.

Indonesia said the area was recognized as its territory under international law.

“Indonesia has a sovereign right to explore the natural resource in that area and that cannot be disturbed by any country,” the agency statement said.

Huge, unexploited oil and gas deposits are believed to lie under the South China Sea’s seabed, though estimates vary greatly.