Apple's online store is offline once again.

Customers visiting the Apple Store online are being greeted by the company's regular message: "We are busy updating the store for you and will be back shortly".

Apple's UK and US stores are both unavailable. While Apple's store updates don't always presage new product introductions or existing product upgrades, they frequently do.

Apple has been previously rumoured to be planning the introduction of a 16GB model of the iPhone this week.