A Sapporo-based TV station has received a letter claiming responsibility for a string of recent gas cylinder bombings targeting police and other facilities in Sapporo and threatening to hit a police box next, sources familiar with the investigation said Thursday.
The letter, sent Tuesday to Hokkaido Cultural Broadcasting Co., said that a "koban" (police box) in the prefectural capital is "the next target" of the bomber. Sapporo police are on full alert.
Five gas cylinder bombs have exploded in the city since late January, striking the parking lot of the Kita Ward Police Station, a police dorm and commercial facilities. All took place within a 6-km wide circular area in Kita Ward.