The announcement comes as the two countries continue to confront each other over disputed territory in the South China Sea and tensions mount over the Philippines' security ties with its ally, the United States.

At least five Chinese nationals were arrested on suspicion of espionage in January and another two in February by Philippine authorities.

The latest arrests in China come two days after the Chinese embassy in Manila issued a travel warning to its citizens about frequent "harassment" from Philippine law enforcement agencies.

On Thursday, state broadcaster CCTV reported that authorities had identified one of the suspected spies as a Philippine national who had lived and worked in China long-term and had been found conducting espionage near military facilities.

The CCTV report included a video of his arrest and what appeared to be a recorded confession.

He was recruited by Philippine intelligence services to "take advantage of his long-term residence in China to conduct espionage activities in China and collect sensitive information, especially on military deployment".

He came close to military facilities multiple times and "conducted close observation and secret photography", CCTV said.

The three individuals had been recruited by the same Philippine spy since 2021 and received regular payment for their work, CCTV said.

They were also tasked with "assisting the Philippine spy intelligence agency in selecting and developing personnel, and expanding its intelligence network in China".

They had provided "a large amount of military-related and confidential video materials" to Philippine agents, "causing serious harm to China's national security and interests", CCTV quoted a Chinese national security officer as saying.