Japanese police today arrested two members of the cultAum Shinrikyofor illegal possession of explosive sodium without a required permit. The arrests came one day after National Police Agency head Takaji Kunimatsu was shot four times by a masked gunman who used a revolver and got away on a bicycle. The cult is suspected -- but denies involvement -- in last week'snerve gas attackon the Tokyo subway system that killed 10 people and sickened thousands. The shooting of Kunimatsu, now hospitalized in serious condition, prompted police to step up their hunt for cult leader Shoko Asahara. Police reportedly want to ask Asahara whether highly educated scientists within the cult made the lethal nerve gas used in the subway attack.