The Pakistan Telecom Authority (PTA), acting on the instructions of the interior ministry, has ordered wireless providers to start re-verifying SIM cards and block any of the 4.47 million SIMs currently unverified, The Nation writes. The regulator, still without a leader at the helm following the sacking of its chairman and the resignation of its two most senior officials earlier this year, was instructed by the interior ministry to ensure that all SIMs must be verified and all unregistered SIMs be blocked. SIM registration has been compulsory in Pakistan since January 2009, but the illegal sale of unregistered SIMs has remained a persistent problem. The re-verification process will require subscribers to send a text message containing their Computerised National Identity Card (CNIC) number, which will generate an automatic reply detailing all the SIMs currently registered to their name. The subscriber must then inform the relevant providers of any SIMs wrongly registered in their name.