The media learned on Sunday that someone posted a bomb threat against Seibu Dome on the popular 2-chan bulletin boards sometime on Saturday morning. According to Tokorozawa police and the Seibu organization, the user threatened to blow up Seibu Dome unless the Softbank-Seibu game was canceled.
Police and stadium staff were increased for Saturday and Sunday's games. No suspicious activity was uncovered. Officials will stay on alert for Monday's game.
Source: Sponichi 10/14/2012
UPDATE 10/15 @ 6:13pm - Some additional notes...
- The post was made at around 3:30am on Saturday.
- Twenty-six police officers, in addition to team staff, patrolled the area around Seibu Dome on Saturday and Sunday.
Source: Nikkan Sports 10/14/2012