India Meteorological Department officials said the quake shook Assam, including its capital Guwahati, Meghalaya, West Bengal and neighbouring Bhutan at 6.35 am.
The epicentre of the tremor was in Kokrajhar at a depth of 10 km on latitude 26.5 degree north and longitude 90.1 degree east, they said.
"We have got information that three persons sustained minor injuries when an old wall collapsed near the Kokrajhar Railway station," Assam State Disaster Management Authority Chief Executive Officer Pramod Kumar Tiwari said.
All the injured were vegetable vendors and being treated now, he said.
"A lion sculpture at an ancient temple in Chirang district fell off its stand during the shock. District officials have visited the place and further information are awaited," Tiwari said.