The Pakistan Telecommunications Authority and mobile phone operators were forced to issue clarifications on Friday after a rumour that people were dying after receiving a call from a particular number triggered panic in the Pakistani city of Karachi.

The rumour had spread like fire since Thursday in the country biggest city with mobile users forwarding and exchanging SMS messages to their friends, relatives and colleagues warning them about the 'deadly' call.

The prank, however, forced the PTA and mobile phone operators to issue statements on television channels insisting all such reports were not true.

"No rays or virus is transmitted from one phone to another and all such reports are untrue," the mobile phone operators said.

A mobile telephone operator said the prankster was probably inspired by the successful horror film The Ring. A similar rumour had sparked panic among residents of Jammu and Kashmir a fortnight back.