A powerful bomb explosion took place near the Congress Bhavan here, damaging the NSUI office and at least 90 people were detained in connection with the incident, police said today.

NSUI office bore the worst brunt of the blast last night, in which window panes of some private shops near the Congress Bhavan- the office of Mizoram Pradesh Congress Committee- were broken, they said.

Police suspect that several gelatin sticks were used to trigger the blast.

Superintendent of Police Lalbiakthanga Khiangte told PTI that 73 people were detained for questioning last night and another 23 were again rounded up today for wider investigations.