A minor explosion occurred last evening near the shoe stand of the Belur Math in which a glass pane of a window was damaged but there was no report of any casualty, the police said.
Three persons were detained today for questioning in connection with the minor explosion at Belur Math, Deputy Commissioner (Head-quarters) of Howrah Police, Nishat Pervez said.
The DC (HQ) said investigations were on and police was examining the CCTV footage in detail.
Meanwhile, the Assistant secretary of the Ramakrishna Math and Mission Swami Suvirananda said police was investigating the matter.
Security had been beefed up in the Belur Math premises after the incident.