Indonesia's President Joko "Jokowi" Widodo has visited the Natuna islands in a move seen as sending a message on Indonesia's efforts to protect its sovereignty over the area in the edge of the South China Sea.

Jokowi, accompanied by top security officials, made the visit Thursday on board the KRI Imam Bonjol, a warship that fired warning shots last week at Chinese fishing vessels in the area and detained one ship and its seven crew members.

He will tour the waters around Natuna and preside over a meeting on the warship to discuss the South China Sea, a presidential office statement said.

On Sunday, China's Foreign Ministry protested last week's incident, saying the Indonesian navy had "abused its military force." It said one fisherman was injured.