Indonesia's President visits Natuna in the South China Sea

In this photo released by the Indonesian Presidential Office, Indonesian President Joko Widodo stands on the bridge of navy warship KRI Imam Bonjol, as it sails on the waters of Natuna Islands, Indonesia, Thursday, June 23, 2016. Widodo visited the Natuna islands Thursday in a move designed to send a message about the country's commitment to protecting its sovereignty in the area at the edge of the South China Sea. (AP Photo/Agus Suparto, Indonesian Presidential Office) (The Associated Press)

In this photo released by the Indonesian Presidential Office, Indonesian President Joko Widodo, third right, accompanied by, from left to right, Cabinet Secretary Pramono Anung, Navy Chief of Staff, Adm. Ade Supandi, top security minister Luhut Panjaitan, Armed Forces Chief Gen. Gatot Nurmantyo and Riau Islands Governor Nurdin Basirun stands on the deck of navy warship KRI Imam Bonjol, on the waters of Natuna Islands, Indonesia, Thursday, June 23, 2016. Widodo visited the Natuna islands Thursday in a move designed to send a message about the country's commitment to protecting its sovereignty in the area at the edge of the South China Sea. (AP Photo/Agus Suparto, Indonesian Presidential Office) (The Associated Press)

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.