Indonesia said it will continue to take "decisive" action against foreign ships operating illegally in waters under its jurisdiction after Beijing criticized its navy for shooting at Chinese fishing vessels.

Indonesian navy spokesman First Admiral Edi Sucipto on Monday confirmed an Indonesian warship fired warning shots at Chinese fishing vessels in waters off Indonesia's Natuna islands and detained one of the vessels and its seven crew members.

He said the incident occurred on Friday. "We will not hesitate to take decisive action against foreign ships, whatever their flag and nationality, when they commit violations in Indonesian territory," Sucipto said.

China's Foreign Ministry released a statement of protest on Sunday and said the Indonesian navy had "abused its military force." It said one fisherman was injured during the incident.

China's expansive claims to the South China Sea do not include the Natuna islands, which are nearly 2,000 kilometers (1,250 miles) from the Chinese mainland in waters between Malaysia and Borneo.

But China's nine dash line, which it uses to roughly demarcate its ambitions for maritime boundaries, overlaps with the section of Indonesia's internationally-recognized exclusive economic zone extending from the Natuna islands. The Chinese foreign ministry's statement characterized the faraway waters as China's traditional fishing ground.

The incident Friday was the third such clash since March, when Indonesia intercepted a Chinese fishing vessel off the Natuna islands. In May, an Indonesian frigate fired shots at a Chinese trawler when it refused to stop fishing, and then seized the vessel and its eight crew members.

Maritime and Fisheries Minister Susi Pudjiastuti, who has overseen the destruction of dozens of foreign boats caught illegally fishing in Indonesian waters, said the navy followed correct procedures for dealing with poachers.

"We don't shoot for no clear reason. Protecting the sovereignty of our country is a must," she wrote on Twitter.