The UK has marked the start of 2017 with a spectacular firework display and a declaration that « London is open ».
Tens of thousands gathered on the banks of the Thames to watch the display immediately after Big Ben sounded its midnight chimes.
New Year events across the UK went ahead under tight security, following lorry attacks in Berlin and Nice.
The music accompanying the London fireworks featured a recording of mayor Sadiq Khan saying: « London is open. »
Other celebrations also took place at popular city locations, including the mass Hogmanay events in Edinburgh, but everywhere there was a more visible police presence with security fears to the fore following a series of terror attacks around Europe in the past year.
News of the latest, an attack which killed at least 35 revellers at a nightclub in the Turkish capital Istanbul, emerged in the final hour of 2016.
In London, around 12,000 fireworks producing 50,000 projectiles lit up the city as part of a 12-minute display.
Music for the display also sampled famous artists who died in 2016, including David Bowie and George Michael.
Mr Khan said before the fireworks that their theme would be « hope and optimism going forward ».
He added the capital was also sending a message to the world that « London is open », particularly post-Brexit, as part of its New Year’s Eve celebrations.
He added: « We’ve always been a city open to talent, to people, to ideas and that is not going to change. »
Singer Robbie Williams staged a live concert from the Central Hall Westminster in London, which was shown on BBC One as part of the New Year celebrations.
After taking a brief break to allow TV viewers and his live audience to take in the Big Ben chimes, Williams returned to the stage to the strains of Auld Lang Syne.
He then restarted his show with his most famous hit Angels, before belting out a version of the traditional New Year favourite New York, New York.
After that, he wound the clock back as he performed his debut single Freedom. Initially released in 1996 after Williams left Take That, it was a cover version of the 1990 hit written and released by George Michael who died on Christmas Day.
As he started the song, he told the audience: « This is dedicated to the legendary George Michael. »
Across the capital security had been stepped up, with more armed officers being deployed and concrete barriers in use.
There were also more places where vehicles are banned.
Greater Manchester Police also increased crowd protection in the wake of the Berlin attack.
British Transport Police « extended » its regular armed patrols across the nation’s rail network and there were armed officers on the London Underground.
Metropolitan Police Det Supt Phil Langworthy said 3,000 officers would be patrolling the streets in London.
Around 75,000 people had been expected to attend Edinburgh’s Hogmanay street party for its sold-out New Year’s Eve celebration.
Police Scotland said there was a « very visible police presence » at the event.
Edinburgh was treated to a total of four separate firework displays to mark Hogmanay.
The Police Federation had made special arrangements to temporarily ban vehicle access in certain parts of London because of the use of lorries as terrorist weapons in this year’s attacks in Nice and Berlin.
Two weeks ago a lorry, driven by Anis Amri, ploughed into a Christmas market in Berlin, killing 12 people and injuring 48.
In Nice in July, 86 people died during Bastille Day celebrations when a lorry drove into crowds on the Promenade des Anglais.