MANILA, Philippines -- The National Bureau of Investigation (NBI) has filed charges against five Japanese nationals who allegedly used a restaurant business as a front for their illegal gambling operations.

Charged with violation of Presidential Decree No. 1602 or illegal gambling before the Cavite Provincial Prosecutor were Osamu Sasai, of Rosario, Cavite; Suzuki Takayuki, Kawano Takashi and Tomiharu Kinoshita, all of Parañaque City; and Takano Issei, of Makati City.

Sasai was reportedly the restaurant owner and operator of the gambling den.

The NBI said the case stemmed from information that the respondents have been using the Sasahama Restaurant on Magdalo Highway, Putol, Kawit Cavite as a front for their illegal gambling operations, particularly mahjong. This prompted the bureau to conduct surveillance operations to verify the information.

Armed with a search warrant issued by Cavite Judge Norberto Quisumbing Jr., agents of the NBI National Capital Region conducted a raid last January 24 that led to arrest of the suspects.

Seized from the suspects were several pieces of Casino Filipino chips, mahjong tables, tiles and markers and one logbook reflecting the "ins" and "outs" of mahjong players.

The NBI also found a box containing documents regarding the gambling activities and a photocopy of a mayor's permit.