British politician Jo Cox was shot dead in a street attack on Thursday afternoon by a gunman who was a "dedicated supporter" of a neo-Nazi group based in the United States.
The 41-year-old politician, who was described as a rising star of the opposition Labour party, was stabbed a number of times and was shot at. The incident happened in her constituency of Birstall, near Leeds in northern England, while she was meeting residents outside a local library.
An eyewitness told BBC they heard the alleged gunman, Tommy Mair, shout "put Britain first" at least twice before the attack. He also attacked another old man in the area and was arrested by the police.
"Britain First" is a far-right anti-immigration group in Britain. Soon after the attack, the group released a statement saying that it was "obviously not involved" and "would never encourage behaviour of this sort."
The Southern Poverty Law Centre said that Mair had a "long history with white nationalism". On their website, they have said: "According to records obtained by the Southern Poverty Law Centre, Mair was a dedicated supporter of the National Alliance (NA), the once premier neo-Nazi organisation in the United States, for decades".
Top politicians including David Cameron, Jeremy Corbyn and US Secretary of State John Kerry expressed grief over the brutal assault.
"It is an assault on everybody who cares about and has faith in democracy," Kerry said. David Cameron tweeted to express his condolences.
Labour leader Jeremy Corbyn described Cox as a "much loved colleague" and said that the country would be "in shock at the horrific murder".
"Jo died doing her public duty at the heart of our democracy, listening to and representing the people she was elected to serve," he said.
"In the coming days there will be questions to answer about how and why she died. But for now all our thoughts are with Jo's husband Brendan and their two young children. They will grow up without their mum, but can be immensely proud of what she did, what she achieved and what she stood for," Corbyn added.
He also referred to Britain's EU membership referendum on June 23 and said that they have planned to suspend all campaigning activities until the weekend as a mark of respect for her.
Fatima Ibrahim, a 23-year-old campaigner with human rights group Avaaz told AFP: "She was a fearless campaigner, and a voice for the voiceless. We feel shaken by her loss, but committed to meeting the hatred that killed her with love. We feel shaken by her loss."
Cox used to work for a charity group called Oxfam before she became a lawmaker in 2015. She had staunchly supported bringing Syrian refugees to Britain.
People left heaps of flowers outside the British Parliament as a tribute for the pro-European Union lawmaker, who is the first British MP after Ian Gow, to be killed in office.
Several activists put up white placard reading messages like "We carry the banner of love for Jo", "you can't kill democracy" and "Thank you for all you did for Syria, for humanity. We will united against hatred".
They also asked other people to add messages as a mark of tribute to Cox. Hundreds of people were seen praying at the local St Peter's church.