HANOI (Reuters) - Indonesia’s navy shot and wounded four Vietnamese fishermen aboard a fishing boat in the South China Sea at the weekend, Vietnamese authorities said.

The Vietnamese boat was about 132 nautical miles (245 km) southeast of Vietnam’s Con Dao island when the fishermen were shot on Saturday night, the Binh Dinh provincial search and rescue committee said on its website.

Disputes over fishing rights and oil drilling have stoked tension in the South China Sea, through which about $5 trillion in goods is shipped each year.

China claims almost the entire sea, but Brunei, Malaysia, the Philippines, Vietnam and Taiwan also have claims.

Although Indonesia says it is not a party to the dispute, it recently renamed the northern reaches of its exclusive economic zone, asserting its own maritime claim.

The coordinates given by the Vietnamese indicated that the shooting happened close to the area Indonesia now calls the North Natuna Sea.

The Vietnamese authorities said two of the fishermen had been seriously wounded. They were taken to Con Dao island for treatment.

Sahono Budianto, an official at Indonesia’s ministry of marine affairs and fisheries, said he was not aware of the alleged shooting.

Indonesia’s navy did not immediately respond to a request for comment.

Indonesia has sunk hundreds of mostly foreign boats caught illegally fishing in its waters since President Joko Widodo launched a battle against the poaching of fish in 2014.

Indonesia and Vietnam said in May they would launch a joint investigation after reports that Vietnamese coast guards had tried to forcibly free five fishing boats and their crew detained in waters near Indonesia’s Natuna Islands.