Indonesia is protesting the Chinese coast guard's rescue of a ship it says was fishing illegally in Indonesian waters.

Foreign Minister Retno Marsudi told reporters after meeting with a senior Chinese diplomat on Monday that the government wants an explanation from Beijing about the incident.

Indonesia says the Chinese vessel was intercepted by a fisheries ministry patrol ship on Saturday within Indonesia's exclusive economic zone which overlaps with the South China Sea. The fishing vessel was being towed when a Chinese coastguard vessel collided with it, allowing its escape.

Marsudi says China's coast guard "violated our sovereignty" and called on China to respect international law.