The quake occurred at 12.08 a.m. The epicentre was in Assam's Sonitpur district bordering Arunachal Pradesh, the regional seismological centre said.
The tremor was felt in Meghalaya, Nagaland, Manipur, Assam and Arunachal Pradesh.
There was no immediate report of damage or casualty.
India's northeastern region is considered the sixth major earthquake-prone belt in the world.