"We have collected their census. The details of their identification numbers and from where they came and their photographs have also been collected in some areas of the city," city Police Commissioner M Mahender Reddy said here.
"It is an ongoing process. We are in the process of collecting all the details and are in the process of having a full-fledged surveillance," Reddy told reporters.
Reddy was replying to a question regarding the arrest of Khalid Mohammed, a Rohingya Muslim, from Hyderabad by National Investigation Agency last month in connection with Burdwan blast.
Hundreds of Rohingya Muslim refugees settled down in various parts of Old City here around last July, following communal violence in Myanmar.