According to the police, there was information that there was a man with a knife in the Shinkansen on the morning of the 11th. The man was taken into custody and handed over to the police at JR Omiya Station in Saitama Prefecture. The police are investigating the situation at that time in detail that there are no injuries to passengers and crew. According to JR East, the man was on the Tohoku Shinkansen from Tokyo to Morioka, which was delayed by about 24 minutes.
Source
A man with a knife in the car of the Tohoku Shinkansen secured no injuries | NHK
