Nigeria's authorities have been forced to reassure the public that a mobile phone number cannot kill, after rumours were spread by text messages.
Viral text messages had warned that several people had died when they answered calls with the ID 09141.
The regulatory body, the Nigerian Communications Commission, said this was "unimaginable" and "unscrupulous persons" were spreading fear.
A BBC reporter was unable to get through to the number.
The text messages gave conflicting accounts of the number of people killed when they answered the call - some put the death toll at seven while others put it at 10.
"Technically, it is not possible for such a thing to happen. It is therefore unimaginable that somebody will die while receiving a call," commission spokesman Reuben Muoka said.
"It is only very gullible people that will believe such a rumour."
Other messages that have caused panic in the past include claims that acid rain from seasonal dust storms can burn people alive, the AP news agency reports.
Poor education and superstitious beliefs lead some Nigerians to take the messages seriously, correspondents say.