A submarine firefight that saw a member of a crew killed on board a Chinese fishing vessel has sparked a new wave of questions about sub-sea warfare.

Key points:Benzene sub-submarine fires two torpedoes and a torpedo launcher in an attempt to ram a Japanese patrol boatA Chinese patrol boat, which is also involved in the firefight, has said it fired warning shots before the sub fired two torpedosThe incident took place in the waters of the South China Sea off the coast of Benelux in the Philippines on Sunday.

A Chinese fishing boat and a Japanese Navy patrol boat were involved in a sub-marine firefight off the southern Philippines, the Chinese navy said in a statement on Tuesday.

In a statement, the PLA said that on Saturday evening a Chinese patrol ship in the Yellow Sea fired warning shot and then fired two torpedo launches.

The statement did not specify the number of torpedoes fired or the nature of the attack, but it did say that the Japanese ship did not respond to the warning shots fired from its submarine.

“The Chinese vessel was attacked with torpedoes which caused considerable damage to the Chinese vessel,” it said.

The attack was the latest in a series of incidents in the South and South China Seas.

Last year, an American warship was shot at by a Chinese submarine, while last year another Chinese vessel engaged in an attack on a Japanese warship.

In 2015, the Japanese navy suffered the loss of a warship, a submarine and a sub, when it was hit by a sub during a drill.

Chinese vessels also shot warning shots from their subs during the incident.

The Philippine Coast Guard said on Tuesday that two Chinese vessels, one of which was a subs, fired warning-shot torpedoes at the US Navy destroyer USS John S McCain.

The Philippines is home to two of China’s most powerful submarines, the Liaoning and the Liaosonde.