Chinese authorities Monday arrested a Japanese citizen suspected of spying, local state media said.

The arrest was made in the port city of Dalian in Liaoning province, which borders North Korea, according to an online report by the official Dalian Daily.

The report said Ken Higuchi is being probed by the Dalian City National Security Bureau on suspicion of spying against China, and that prosecutors had approved his arrest.

The kanji given for Higuchi's given name can also be pronounced Takeshi or Takeru.

It was unclear from the report, however, whether Higuchi was a new case or whether he had been detained earlier, and the latest development was just his formal arrest.

China detained six Japanese nationals in March on suspicion of illegal activities. Four returned to Japan in July, three of whom were there doing geological research into hot springs, according to their employer.

China's foreign ministry also said in July that a single Japanese was being investigated on suspicion of harming national security.

The Foreign Ministry in Tokyo did not immediately comment. Monday was Respect for the Aged Day, a national holiday.

China's relationship with Japan has been strained for decades over the legacy of Japan's wartime aggression, while the dispute over the Senkaku Islands in the East China Sea has in recent years added to the mutual suspicion.

In 2010, four Japanese were detained in China on suspicion of entering a military zone and taking photographs without permission.

At least two Japanese citizens were arrested on suspicion of espionage in 2015. Last year, China said it was investigating a Japanese citizen on suspicion of endangering national security.