There has been a clash in the South China Sea over a move to intercept a vessel said to be fishing illegally. Indonesia has accused a Vietnamese coastguard ship of ramming one of its vessels on the weekend in a bid to stop a Vietnamese boat from being impounded for fishing in waters that it claims exclusively.

The clash saw Jakarta summon Vietnam’s ambassador on Monday, after a dozen Vietnamese fishermen were detained by the Indonesian navy.

The drama also prompted a senior Indonesian minister to announce a return to sinking foreign trawlers.

“The actions taken by the Vietnamese coastguard ship endangered the lives of officers from both countries and is not in accordance with international law or the spirit of ASEAN (the Association of Southeast Asian Nations),” Indonesia’s foreign ministry said, according to AFP.

Jakarta claims the area in the southernmost reaches of the South China Sea as its economic zone – and the exclusive right to exploit resources.

The navy said two Vietnamese coastguard ships tried to prevent an illegal fishing boat from being apprehended by ramming its vessel.

Indonesian authorities later said the fishing boat sank, possibly due to an accidental collision. They did not elaborate.

A dozen fishermen were detained and remain in Indonesian custody. Two others escaped detention by jumping into the water. They were picked by the Vietnamese coastguard, which then fled, the navy said.

Video circulating on social media purported to show a Vietnamese patrol boat ramming the left side of the Indonesian vessel as the armed navy crew shouted abuse.

A screen grab taken after the Vietnamese coastguard vessel hit the Indonesia navy boat off Borneo on April 27, 2019. Photo: Indonesian navy / AFP

Indonesia, the world’s biggest archipelago nation, has been trying to stop foreign vessels fishing illegally in its territory, claiming it costs the economy billions of dollars annually. It turned to a campaign of blowing up captured foreign boats as a deterrent.

Hundreds of detained foreign fishing vessels have been sunk, including many Vietnamese boats – after the crews were removed – over the past five years, with some blown up in spectacular public displays.

The practice was suspended for several months, but Indonesian fisheries minister Susi Pudjiastuti announced on Monday that it would resume this weekend.

“On the 4th (of May) we will be sinking 51 boats, mostly from Vietnam!” AFP said Susi did not say if it was in retaliation for the latest diplomatic clash with Vietnam.

Two years ago, Indonesia changed the name of the southern part of the South China Sea to the North Natuna Sea in a bid to show its sovereignty.

More recently, it inaugurated a new military base in the chain of several hundred small islands to beef up its border defense.

The moves have prompted criticism from Beijing whose claims in the sea overlap with Indonesia’s claim around the remote Natuna Islands.

With reporting by AFP