The iPhone 6S and iPhone 6S Plus are now on sale from Apple Stores in the UK, with eager fans queuing overnight in order to be among the first to get their hands on the phones.
Apple had to hold the queue around the side from its flagship Regent Street store (shown above), before finally letting the early buyers inside, to the usual cheering and clapping from Apple Store staff, as the video below shows.
Apple's rival Samsung attempted to gatecarsh the occassion, with staff employed to parade around with giant flags being used to promote its new Galaxy S6 Edge and Edge+.
The new iPhones are also available to buy from the Apple online store as well via certain networks and third-party retailers.
However, those wanting one of the new models could face a long wait if they have not already pre-ordered a device, as Apple has already updated the delivery information about the models to adjust shipping estimates.
All the iPhone 6S models, in the four different colour options and three different storage versions, are currently set to ship within one to weeks of the models going on sale.
However, every iPhone 6S Plus model is now listed as shipping in three to four weeks.
The iPhone 6S and iPhone 6S Plus were made available to pre-order from the Apple web store on 12 September.
The iPhone 6S is available in 16GB, 64GB or 128GB models, which cost £539, £619 and £699 respectively. The iPhone 6S Plus is more expensive at £619, £699 and £789 for 16GB, 64GB or 128GB respectively.
The models come in four colours now, with a rose gold option added alongside silver, gold and space grey.
Apple unveiled the iPhone 6S and iPhone 6S Plus smartphones at an event in San Francisco on 9 September, boasting of advanced 3D Touch technology for improved screen interactions and a camera lens that can shoot 4K video.
The phones will be available from 25 September in the UK, US, China, France and Germany, among others. It will reach 130 countries by the end of the year.
Apple has revealed that pre-orders for the iPhone 6S and iPhone 6S Plus are already on track to exceed the 10 million record set last year.
The firm said in a statement sent to CNBC that pre-orders had been “very strong” around the world and that customer response to the new devices is “extremely positive”.
"We are on pace to beat last year's 10 million unit first weekend record when the new iPhones go on sale on 25 September," Apple said.
Apple added that demand for the larger 5.7in iPhone 6S Plus had been even greater than imagined, which had forced order times back by up to three to four weeks. The firm is working with suppliers to reduce this backlog.
"As many customers noticed, the online demand for iPhone 6S Plus has been exceptionally strong and exceeded our own forecasts for the pre-order period," it said.
"We are working to catch up as quickly as we can, and we will have iPhone 6S Plus as well as iPhone 6S units available at Apple retail stores when they open next Friday."
The iPhone 6S retains the same dimensions and 4.7in screen as the original model, while the iPhone 6S Plus has the same 5.5in screen.
Marketing chief Phil Schiller showed off a major new improvement in the form of 3D Touch, which offers more advanced interaction with the iPhone screens depending on how hard or gently you press the screen.
Design chief Jony Ive termed these actions as 'peek' and 'pop', so you can bring up more information from an app by 'peeking' into it, or move from one app to another - say from texts to maps - by 'popping' it open by holding down an address for a certain length of time.
The phone also has a new A9 chip that Schiller said is 70 percent faster at CPU tasks and 90 percent faster at GPU tasks than the A8 chip.
The iPhone 6S and iPhone 6S Plus also have new 12MP iSight cameras and will be able to take 4K video. The front-facing FaceTime camera has been upgraded to 5MP.
Apple also showed off what it called 'live photos' that adds movement to photos, essentially creating a short video or gif clip as well as the photo.
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