Half a dozen new cases of "exploding iPhones" have emerged in France, as Apple faced an official inquiry and calls to come clean over possible risks linked to its wildly popular smartphone.

An 80-year-old pensioner from the Paris suburbs said his iPhone screen cracked up in his hands, a day after a supermarket watchman claimed he was hurt in the eye when his screen suddenly shattered this week.

Ten French consumers have now come forward saying their iPhone screens exploded or cracked without explanation, according to an AFP tally, including a first case in mid-August in which a teenager suffered an eye injury.

Apple is accused of trying to hush up 15 cases of iPod music players heating up and bursting into flames in the United States and in one similar British case, all apparently due to overheated lithium ion batteries.

None of the incidents has caused a serious injury but Apple was forced to defend the safety of its flagship smartphone before the European Union this month, insisting the exploding screen cases were "isolated incidents".