Four senior members of a group suspected of organizing scams and burglaries in Japan from the Philippines were served fresh arrest warrants Tuesday for allegedly orchestrating a robbery that resulted in injuries in western Tokyo last year, police said.

The latest arrests, including of Kiyoto Imamura, 39, who the police suspect used the pseudonym "Luffy" when planning and coordinating the crime, mark the final charges from eight cases of burglary across the country subject to intensive police investigation since June.

The other three suspected of orchestrating trespassing into a home in Inagi, western Tokyo, in October last year, beating its residents and robbing them of gold and cash are Yuki Watanabe, 39, Toshiya Fujita, 39, and Tomonobu Kojima, 45, police said.

The four men are believed to have coordinated the robbery remotely via an encrypted messaging app while being held at an immigration detention facility in Manila. They were deported to Japan from the Philippines in February this year.

Additional arrest warrants were served for Watanabe and Fujita for allegedly planning a robbery in Oamishirasato in Chiba Prefecture, as well as Kojima for his suspected involvement in robberies in Iwakuni, Yamaguchi Prefecture in November last year and in Tokyo's Nakano Ward the following month.

Imamura, Watanabe and Fujita have also been indicted on charges of robbery resulting in the death of a 90-year-old woman at her home in Komae, western Tokyo, in January.

Tokyo police set up a joint investigative headquarters with prefectural police departments in Chiba, Kyoto, Hiroshima and Yamaguchi in June, seeking to build cases for the eight robberies alleged to have been carried out by the group.

The police believe that Imamura used aliases, such as "Luffy," when ordering the crimes to be carried out in Japan.

Those who committed the burglaries are believed to have been recruited online for "yami baito," literally meaning "dark part-time work."

The four men were initially arrested for alleged theft in connection with scams targeting people in Japan.