New Delhi, Jan. 3 :    New Delhi, Jan. 3:  The Centre is shutting down public phone booths offering long-distance call facilities and Internet cafes in the border districts of Punjab, Rajasthan and Gujarat, widening a clampdown that began in Jammu and Kashmir. 'The letters have been sent to district magistrates in the three states to take immediate action for closing down PCOs (public call offices) with STD/ISD services. They will coordinate with Bharat Sanchar Nigam Ltd (BSNL) and private operators,' a home ministry official said. The campaign, spurred by security concerns, is being intensified despite an indication by communications minister Pramod Mahajan today that the controversial closure order in Jammu and Kashmir would be reviewed. Sources in BSNL, too, said the home ministry had approached them on the feasibility of widening the STD/ISD booth ban to new areas which the ministry felt were 'sensitive'. 'A few places in Rajasthan, Punjab and Gujarat will be affected. The PCOs and Internet cafes will be asked to close shop and their connections will be cut. We are awaiting the list of places where PCOs and Internet cafes will have to be closed,' a a BSNL official said. 'Customers will suffer but we are helpless since the company is bound by the directives of the government and it is a issue of national security,' he added. Mahajan said during the day that the government had 'enough reasons' for restricting PCO users from making STD and ISD calls. Officials said private operators will also be affected as they are present in these three states. A senior executive of one of the telecom companies said: 'We had jammed all calls to Pakistan soon after the December 13 attack and we will follow whatever steps needed to be taken in the interest of national security.' Communications ministry sources pointed out that licence conditions allow the government to ask operators to jam calls or hand over facilities to official agencies whenever security considerations demand so. BSNL officials said these measures would help check flow of information to terrorist groups as well as foreign intelligence agencies. But they added that 'terrorists or spies can use other sophisticated means like satellite phones which are difficult to track. They can also travel to those areas where the ban does not exist to transmit information.' The only way to counter this is to closely monitor telecom networks and Internet traffic. This requires more personnel and sophisticated tracking equipment, which the government would find difficult to install fast.