China accuses Indonesia of injuring fisherman, charges the latter has denied.
Indonesia said on Monday it will continue to protect the sovereignty of its fishing grounds following reports of a fresh confrontation with Chinese vessels in the disputed South China Sea.
An Indonesian naval vessel fired on a Chinese fishing boat, injuring one person, China's Foreign Ministry said late on Sunday. Indonesian Foreign Minister Retno Marsudi on Monday denied reports that Chinese crew had been injured.
This is the third reported confrontation between the two countries in 2016 near the Natuna Islands, as regional tensions mount in the sea.
Marsudi said, "I have been communicating with our army commander and naval chief, and no boat crew were injured."
When asked about the incident, Indonesian Vice President Jusuf Kalla said they wanted to get a message across to "the other side" to honour the area according to the law.
"This is not a clash, but we are protecting the area," added Kalla. He said the government will continue to be more assertive.
Indonesia's navy said it had fired warning shots at several boats with Chinese flags accused of fishing illegally near the gas-rich Natuna Islands.
Navy spokesman Edi Sucipto said, "Whatever the flag, when they commit violations inside Indonesia's jurisdiction, we, in this case, the navy, will not hesitate to act decisively."
Indonesia is not part of the broader regional dispute over China's reclamation activities in the South China Sea and Beijing's claims on swathes of critical waterways.
But Jakarta has objected to China's inclusion of parts of the Indonesian-governed Natuna Islands within the "nine-dash line" Beijing marks on maps to show its claim on the body of water.
China has said it does not dispute Indonesia's sovereignty over the Natuna Islands, although the statement said the area where the incident occurred is subject to overlapping interests.
The Indonesian warship damaged a Chinese fishing boat, injuring one crew member, while seven people onboard another vessel were detained by Indonesia, Chinese Foreign Ministry spokesperson Hua Chunying said in a statement on an official website.
Hua said the Chinese Coast Guard rescued the injured fisherman, who was transported to the southern Chinese island province of Hainan for treatment.
It was unclear whether the Chinese fishermen or the boat was still in Indonesia custody.
Beijing has protested the incident through diplomatic channels, added her statement, which urged Indonesia not to take any more actions to complicate the situation.
Fishing for trouble
There were two other encounters reported between Indonesian naval vessels and Chinese fishing boats near the islands this year.
In May, Beijing lodged a strong protest after the Indonesian Navy seized a Chinese boat in waters near the Natuna Islands for allegedly fishing illegally.
In March, the Chinese Coast Guard rammed a Chinese boat detained near the islands and helped it escape as the Indonesians were towing the vessel to shore.
Jakarta responded furiously, lodging a protest and summoning China's top envoy in the country.
China asserts authority over almost all of the South China Sea despite partial counter-claims from several southeastern Asian nations.
Unlike its neighbours, Indonesia does not claim ownership of reefs or islets in the sea. But it objects to Beijing's claims because they overlap with its exclusive economic zone around the Natuna.
Indonesia has launched a tough crackdown on illegal fishing in recent months, sinking foreign boats after removing their crews.