A look at security preparations in some of Europe's major cities, where thousands are expected in the streets to see in the New Year.
Cities across Europe are on alert in the run-up to New Year’s Eve, as the threat of terrorist attacks continues to hang over the continent. Here is a look at plans in some Western European nations.
Police in Madrid have stepped up security, with measures including a ban on lorries and vans in the centre of the Spanish capital during the festivities.
The number of people packing into the emblematic Plaza del Sol in central Madrid to bring in the New Year will be reduced from 25,000 to 20,000. Stricter-than-usual security checks will also be introduced, with no glass bottles, flags or flagpoles to be allowed into the area.
Italy’s Interior Ministry ordered security to be tightened before Christmas for the festive period, including for New Year’s events.
Local authorities have been told to step up security in areas expected to be filled with people, and at attractions that regularly attract crowds.
Traffic restrictions and the use of metal detectors are part of Rome’s festive public safety plan with tight security, notably around the city’s main squares.
Armed officers will patrol the streets of London as the city prepares to mark the New Year with its traditional fireworks display.
Police said a range of security measures had been in put place after a series of terror attacks struck the city this year.
Hundreds of thousands of people are expected to line the banks of the River Thames to welcome the first moments of 2018, with a fireworks show centred on the London Eye.
Metropolitan Police spokesman Nick Aldworth said: "As they come into the footprint they will see an effective search and secure regime, they will see physical barriers, they will see uniformed police officers, they will see visible uniformed private security contractors.
"What they won't see is a number of covert resources that are also working alongside us to keep this event safe."
There were four major terrorist incidents in London in 2017, including an attack on the Houses of Parliament in March in which a police office and four other people were killed.
In June, eight people died when armed men stormed a marketplace near London Bridge.
The city also saw smaller-scale attacks near a north London mosque during Ramadan and on a commuter train in southwest London.
The Metropolitan Police said there was no specific intelligence of an attack on New Year's Eve but urged people to remain vigilant.
Germany is on high alert a year after a deadly truck attack on a Christmas market in Berlin.
Barricades around the Brandenburg Gate will reassure revellers. And there will be a safe zone for women at the site after hundreds were molested and robbed in Cologne on New Year’s Eve two years ago.
Berlin police say the safety area in the capital’s “party mile” around the gate will feature tents, with German Red Cross staff including psychologists on hand for women feeling harassed.
The move has proved controversial. The head of Germany’s second-largest police officers’ union said a women’s zone planned for Berlin sent a “disastrous message”.
“With this message, you’re saying that there are safe and unsafe zones,” Rainer Wendt told the Neue Osnabrücher Zeitung newspaper. He said the move would amount to “the end of equality, freedom of movement and self-determination,” adding that women had a right to be safe everywhere.
In Cologne, police say 1,400 police officers are to be deployed on the central railway station plaza and around the adjacent cathedral. Fireworks are to be banned, while there have been plans for more video surveillance cameras and improved lighting.
The events in Cologne made worldwide headlines two years ago when groups of young men of North African appearance molested hundreds of women in the city centre.