evidence: The incident happened on Friday near the Natuna islands, off the coast of Borneo in the South China Sea. [...] China accepts the Natuna islands and the seas around them belong to Indonesia, but the two sides have confronted one another there before, typically over illegal fishing. [...] In March, Indonesia lodged an official protest after an Indonesian patrol ship tried to detain a Chinese fishing boat in the Natuna Sea, but was prevented from doing so by the Chinese coastguard.