"There was an incidence no doubt but all have returned," he said while referring to the ethnic riots between Bodos and minorities earlier this year.
The situation was "under control" now, he said on the sidelines of PanIIT Global programme here, adding that, "I don't know if anybody is still staying in north Bengal."
"If you have, give us a list of the exact number of people (from Assam in north Bengal)," he said while replying to questions from the media.
Four BTAD districts and neighbouring Dhubri was rocked by ethnic violence in July-August and in November this year which claimed about 100 lives and made over four lakh people flee their homes.