NEW DELHI (Agencies) - Indian government has arrested a few persons from Supaul (Bihar) and Birbum (West Bengal) who have been involved in smuggling of nuclear material and technology to several countries, including Iran. They are linked with a group that carries on its activities with impunity in collusion with police, customs, and other functionaries of law-enforcing agencies. The smugglers are linked with West-Bengal-based Maheshwar Deo Singh's network that supervises illegal transportation of nuclear materials in several Indian states and across the borders. India's Department of Atomic Energy has expressed its concern over leak of information to media about illicit trafficking of nuclear materials and technology as this could tarnish India's image as a state committed to non- proliferation. Consequently, India's Home Ministry has issued a circular to chief secretaries of all Indian States and Union Territories to do their best to forestall publicity of nuclear theft or smuggling incidents.   It is significant to note that the IAEA has appreciated steps taken by Pakistan to secure its nuclear materials. There is not a single incident of nuclear proliferation recorded in the ITDB, subscribed to by Pakistan through its Nuclear Regulatory Authority. In its recently - released Illicit Trafficking Database Report, the IAEA has revealed 827 confirmed incidents involving nuclear, radioactive materials and radioactively - contaminated materials, from 1993-2005. Pakistan is not involved in any of these incidents.