There was a document that claimed there had been 3 such events on Shell petrol station forecourts. It got circulated by my company's health and safety department to all staff.
This from Shell's website:
We understand that there is an email, purportedly official Shell communication, circulating which describes various incidents that are supposed to have occured as a result of mobile phones ringing while at a retail station.
Please be advised that the email in question does NOT originate from Shell Malaysia and we are unable to confirm any of the incidents quoted.
Urban myth....?