Militants exploded a powerful bomb at the private residence of Manipur Assembly Speaker Maniruddin Shaikh minutes after he left the house at Lilong area in Thoubal district on Wednesday.
Shaikh lives at his official residence in Imphal.
Sources said three youths sustained injuries by the splinters of the bomb. Their condition was stated to be critical.
The police are investigating whether the incident was related to monetary demand by militants from the speaker, the sources said.