A grenade was lobbed at the house of Union Minister Rajen Gohain in Nagaon town, but there was no casualty as it did not explode.
A police official said that eye witnesses had claimed that two motorcycle-borne miscreants hurled the grenade post midnight at the house of Union minister of state for railways.
No one was injured as the grenade did not explode, the official said.
Security forces, which rushed to the spot, later defused the grenade.
The miscreants immediately fled the scene after hurling the grenade.
Gohain and his family were not in Nagaon and only security guards were posted at the house.
Police have launched an investigation to find if any militant group is involved in the attack.