Apple has issued a recall notice for the ultracompact USB power adapter shipped with the iPhone 3G in certain countries, although not the UK.

Apple says that "under certain conditions the new ultracompact Apple USB power adapter's metal prongs can break off and remain in a power outlet, creating the risk of electric shock".

"Apple has received reports of detached prongs involving a very small percentage of the adapters sold, but no injuries have been reported."

The company says it has voluntarily decided to exchange every ultracompact power adapter for a new redesigned adapter, free of charge.

Counties affected are the US, Japan, Canada, Mexico and several Latin American countries. Customers can either order a new adapter online, or go into their local store for a direct swap.