Security agencies have expressed concern over the new encryption feature introduced by popular messaging giant WhatsApp saying it could be misused by anti-national elements for achieving their nefarious designs.

The just-introduced end-to-end encryption of WhatsApp will protect texts and voice calls and gives no access to the security agencies, making it much tougher for them to tackle any situation arising out of messages, videos being circulated through the messaging service.

WhatsApp has puts out a one-line advisory to its users: Messages you send to this chat and calls are now secured with end-to-end encryption.

"The move is a potential security threat," said a security official.

WhatsApp's action came close on the heels of a legal battle between Apple and FBI over the US agency's demand that the iPhone maker help unlock its mobile phones.

The popular messenger was being used excessively in Jammu and Kashmir by separatists and anti-national elements for spreading rumours which have often led to violent clashes.

The security agencies will be taking up the matter with the Telecom ministry to ensure that proper safeguards are in place before the services could be allowed in the country, the sources said.

In the past, the government had red-flagged BlackBerry Internet Services (BIS), BlackBerry Messenger (BBM) and BlackBerry Enterprise Servers (BES) of smartphone maker Research-In-Motion (RIM) until the company installed a server within India for real-time information to the security agencies.