Bangladesh today tightened the rules on the sale and registration of mobile phones in a bid to crack down on the increasing criminal use of handsets, dpa quoted officials as saying. The regulatory authorities have so far blocked as many as 200,000 numbers following the use of phones in criminal activities such as extortion and issuing death threats. From now on, subscribers must produce their national identity card in order to register a new Subscriber Identity Module (SIM) card, said Home Minister Shahara Khatun. She added that subscribers must also be over 18 years old, and mobile operators must obtain a police report before appointing anyone as a salesperson. The Home Minister's directive was in line with recommendations from a national committee set up to combat the use of mobile phones in criminal activity. "SIM cards are now so widely available that you can get one even from a betel-leaf seller. The extortionists and criminals are using SIM cards which are not properly registered," the minister said. She added that the production and inclusion of each buyer's national ID number will be made mandatory for registration of a SIM card. Bengali police receive at least 150 complaints everyday from individuals - including some eminent Bengali citizens - who have been threatened by anonymous callers, according to an intelligence official. Figures from the Bangladesh Telecommunications Regulatory Commission indicate that six mobile phone operators had some 53.83 million active subscribers across the country as of January 2010.