A powerful bomb exploded at New Chekon area in the heart of the city in Imphal on Tuesday.
The bomb planted by militants went off at 4 am, damaging a car, official sources said.
Police said it was targeted at security and police personnel who frequent the area.
Police is investigating how militants entered the area despite a tight security deployment.
In interior Thoubal district, a bomb-like object was found at Khongjom-Wangjing area, the sources said.