Philippine naval authorities have detained six Chinese fishermen for alleged poaching in the country's territorial waters, police said Sunday.

The fishermen's vessel was intercepted Thursday off the coastal town of Balabac in Palawan, a western island facing the South China Sea where both countries have overlapping territorial claims.

"Recovered from their possession and control were eleven sea turtles, fish nets and other paraphernalia," national police spokesman Chief Superintendent Agrimero Cruz said.

He said the six have been detained and their boat confiscated while charges were being prepared against them.

It was not clear whether the Chinese Embassy in Manila had been informed of the incident, and no one from the embassy was immediately available to comment.

Hundreds of Chinese fishermen have been caught allegedly poaching in waters off Palawan over the past decade, but all have eventually been freed and deported to China.

China claims ownership over all of the South China Sea on historical grounds, and its fishermen often stray close to Philippine shores.

In October, the Philippine navy seized 25 small Chinese fishing boats being towed by a larger vessel, also off Palawan.

The bigger vessel escaped after the navy confronted it near Reed Bank, just 150 kilometres (90 miles) from Palawan.

Taiwan, Vietnam, Brunei and Malaysia also have competing claims to parts of the South China Sea.

Vietnam and the Philippines have complained of increasing Chinese aggression in the area, but a proposal made by Manila at a recently concluded East Asian summit seeking a stronger regional front against Beijing failed to gain traction.