Pakistan Telecommunication Authority (PTA) in collaboration with Federal Investigation Agency (FIA) conducted these raids during the period as part of its measures to curb grey telephony.
The estimated loss of grey traffic cannot be predicted, but the raids conducted so far led a saving of hefty amount.
The PTA sources on Tuesday said to curb grey traffic, a Technical System has already been deployed for monitoring and reconciliation of International Telephone Traffic with funding of Long Distance & International (LDI) operators in the light of International Clearing House (ICH) Policy Directive issued by Ministry of IT last year.
The System, called Grey Traffic Mitigation System (GTMS), became operational on two months back and is capable to automatically block those Internet Protocol (IP) addresses which are not in the authorized Whitelist.
Moreover, the sources said the Authority, in order to educate and involve the public to report any international calls received with local Caller Line Identification (CLI) had advertised in newspapers and was also initiating a media campaign through Cellular Mobile Operators.
It has also established a Call Center for general public to report international calls received showing local numbers to PTA. The Call Center can be approached through following access points: Toll free: 080055055, Short code: 8866, Phone No. 0519207059, Email: complaint@pta.gov.pk and Fax No. 0512878127.