London and other British cities lit landmark buildings in the red, white and blue of the French flag in solidarity after Paris gun and bomb attacks killed 129 people.
Some two thousand people gathered at an evening vigil yesterday in the capital's Trafalgar Square, where fountains and the grand portico of the National Gallery opposite were lit to resemble the Tricolour.
London landmarks the National Theatre, London Eye ferris wheel and Tower Bridge were also bathed in the French colours, joining other iconic buildings in Edinburgh, Glasgow, Liverpool, Birmingham and Leeds.
"I feel sorry for the French, I've got friends in France. These kind of attacks could happen anywhere," said Oliver McQueen at Trafalgar Square.
"I'm upset ... So many innocent people killed for nothing."
At times the crowd transformed into a sea of light as hundreds simultaneously held up mobile phones and candles as they sang France's national anthem and chanted the French motto "Liberte, egalite, fraternite".
"At times like this it's important to show solidarity with the French people, especially since we're so close to Paris, it could easily happen here," said British student Alice Zhao, 18.
The French embassy became a shrine to those killed in Friday's attacks, with around 60 bouquets laid at its front step.
"I just felt numb. It was just a sense that this kind of thing isn't really a surprise anymore. It just happens over and over and over," said Jonathan, 24, who cycles past the embassy on his commute to work.
Andrey Sidelnikov, a Russian national, said: "We need to tell the all the world that we want to live in peace, only in peace. We don't want to live in war".
At London's St Pancras International station, terminal for the Eurostar train service to Paris and other continental destinations, at least a dozen police officers patrolled the concourse, some carrying arms.
"It was sad, really sad. Not a lot of people in the streets, a lot of people staying home. Everyone looking down, or looking suspiciously," said French student Daria Putilina, who had arrived from Paris.
Pam, a British tourist, said: "Paris was quite quiet. I didn't feel afraid, and I would not have cut my trip short if I wasn't returning today.
