The tremor, which occurred at 9.46 AM and lasted a few seconds, caused cracks to appear in the building of a middle school in Golaghat district, official sources said.
As scared students attempted to flee they fell and six of them were injured, the sources said, adding they were allowed to go after first aid.
The quake caused cracks in some other government school buildings as well and caused chunks of plaster to fall from the ceiling, they said.
The epicentre of the tremor was in Karbi Anglong district at a depth of 20 km on latitude 26.5 degree north and longitude 93.5 degree east, Met office here said.