Apple said that first weekend sales of its iPhone 5 had topped five million units, noting that “demand for the iPhone 5 exceeded initial supply”. The figure compares with four million for the first weekend of the iPhone 4S, although the new device is also available in two additional markets.

In a statement, Tim Cook, Apple’s CEO, said: “While we have sold out of our initial supply, stores continue to receive iPhone 5 shipments regularly and customers can continue to order online and receive an estimated delivery date.”

The five million number was below many analyst expectations, some of which were as high as 10 million units. Shaw Wu, an analyst with Sterne Agee, summed up the situation: “We find it unfortunate that some analysts continue to publish irresponsible estimates without taking into account realistic demand trends and potential supply constraints on new in-cell touchscreens”.

According to the Wall Street Journal, while Apple’s own stores in the US had plentiful supplies, “other retail chains that offered the device had limited quantities from the outset”. It is not clear if this situation also applied to Apple’s operator partners.

The iPhone 5 is set to ship in 21 additional markets across Europe, plus New Zealand, later this week. While this will enable the company to grow its unit shipments significantly, there has been some question as to whether Apple will be able to supply enough devices to meet demand.