The attempts to elicit information sources say, come in the light of heavy military deployment and operational movements along the Indo-Pakistan International Border in the wake of the ongoing Operation Vijay in the Kargil sector.

Army sources say that over the past few days there have been a large number of calls to army offices in various stations, by persons claiming to be officers and trying to elicit information about whereabouts of some officers or their activities.

Army sources do not rule out the possibility of some damage to operational security having been already done. "There have been reports of such calls being received earlier also. But of late they have started targeting strike formations in order to learn their whereabouts or movements of their sub-formations," an officer here commented. "This has forced us to bar access to any outside caller," he added.

Civilian access to military telephone network was blocked two days ago. Sources say that this is a temporary measure and direct access would be restored when the situations so warrants.

As per the new operating system, direct access from a civil line to Army telephones available earlier by adding a prefix to the military number has been stopped. Even access to individual scribers through the military exchange has been barred. Callers are now required to leave their name and number with the operator, which is then forwarded to the concerned person. The person, if he so desires, can then call back. A record of all calls being made to military exchanges is being maintained.

Sources say that even after access was blocked, attempts to get across via the exchange were reported. However, such calls were abruptly terminated when asked for the caller's identification.

Moreover, individual subscribers could also be accessed either directly or through military exchanges, which have civil numbers, through International Straight Dialling (SD). "This means that anyone sitting across the border could simply lift a phone and dial a number if it is known and talk to anyone here."

"For instance, a phone may be attended by a jawan in the absence of an officer and the caller on the other end pretending to be some senior officer from another station or formation, may end up getting some information as to the officer's activities like his whereabouts, duration of absence, future engagements and so on," pointed out an officer. "Such tit-bits when collected and collated with other information collected by different means, gives out a larger picture of what is going on," he added.

For its own communication needs, the Army has a separate nation-wide telephone network, called the Army Static Communication Network (ASCON), operated by the Corps of Signals. Secure from tapping, it links different stations on a dedicated network of land lines, which cannot be accessed by non-military telephones.

This preventive measure has also created problems for Army personnel and their families as relatives or friends particularly from other stations, trying to reach them cannot get through.