The Indian government confirmed the death toll on Monday morning, saying at least 33 people were also injured in the earthquake which struck near the city of Imphal.
Another man was reported dead in Bangladesh after apparently suffering a heart attack following the quake.
Dozens more were injured in the scramble to escape buildings in India and Bangladesh after they were woken by the early morning tremor.
The US Geological Survey said the quake hit at 4:35am local time (23:05 GMT Sunday), 29km west-northwest of Imphal, capital of Manipur state, where dozens of buildings were damaged.
A resident in Imphal told Al Jazeera that the earthquake was the largest he has ever felt.
"People came running out of their homes screaming, some crying," he said, adding that a heavy bell at a nearby temple began ringing immediately after the quake.
Indian Prime Minister Narendra Modi tweeted that he had spoken to local authorities in Assam about the impact of the quake.
The tremors were felt as far away as Kolkata some 600km distant in the Indian state of West Bengal, where buildings shook.