Apple has warned iPhone users that its smartphones could possibly interfere with medical equipment, including pacemakers.

Apple, in a notice on its support page on Saturday, expanded on its previous safety information by warning users that iPhones contain magnets and radios which emit electromagnetic fields.

According to the premium mobile device manufacturer, both magnets and radio "may interfere" with medical devices including defibrillators and implanted pacemakers.

The notice singled out users of all the four iPhone 12 models and MagSafe accessories saying they had "the magnets inside" and that it was more than in previous iPhone models.

However, Apple said they do not pose a greater danger of magnetic interference with medical devices than earlier models.

The Tim Cook headed company noted that medical devices could contain sensors that may react to magnets or radio waves if the mobile devices come in close proximity to them.

Apple urged users of the said iPhones and MagSafe chargers to keep them a "safe distance" away from medical devices, proposing more than 6 inches apart, or 15 inches apart when wirelessly charging.

The iPhone 12 models were launched late last year as Apple announced the return of MagSafe chargers for the device.

Apple adviced customers that if they felt like their iPhone 12 or MagSafe charger interfered with their medical devices, they should cease using them immediately.

All iPhone 12 users were also asked to avoid placing credit cards, security badges, passports or key FOBs between their phone and MagSafe charger when not using MagSafe chargers.

According to Apple, the magnets could damage magnetic strips or RFID chips in those items.