A British member of parliament was shot dead in the street on Thursday, causing deep shock across Britain and the suspension of campaigning for next week's referendum on the country's EU membership.
Jo Cox, 41, a lawmaker for the opposition Labour Party and a vocal advocate for Britain remaining in the European Union, was attacked while preparing to meet constituents in Birstall near Leeds in northern England.
Media reports said she had been shot and stabbed. West Yorkshire regional police said a 52-year-old man was arrested by officers nearby and weapons including a firearm recovered. "We are not in a position to discuss any motive at this time," said Temporary Chief Constable Dee Collins.
One witness said a man pulled an old or makeshift gun from a bag and fired twice. "I saw a lady on the floor like on the beach with her arms straight and her knees up and blood all over the face," Hichem Ben-Abdallah told reporters. "She wasn't making any noise, but clearly she was in agony."
Media reports, citing witnesses, said the attacker had shouted out "Britain first", which is the name of a right-wing nationalist group that describes itself on its website as "a patriotic political party and street defence organisation".
But the deputy leader of the group completely distanced it from the attack, which she described as "absolutely disgusting".
The rival referendum campaign groups said they were suspending activities for the day, with the Remain camp saying its activities would also be suspended on Friday. Prime Minister David Cameron said he would pull out of a planned rally in Gibraltar, the British territory on the southern coast of Spain.
Cameron said the killing of Cox, who was married with two children and had worked on U.S. President Barack Obama's 2008 election campaign, was a tragedy.
"We have lost a great star," the Conservative prime minister said in a statement. "She was a great campaigning MP with huge compassion, with a big heart. It is dreadful, dreadful news."
It was not immediately clear what the impact would be on the referendum, which has polarized the nation into pro- and anti-EU camps. But some analysts speculated it could boost the pro-EU "Remain" campaign, which in recent days has fallen behind the "Leave" camp in pre-referendum polls.[
Britain's sterling currency strengthened against the dollar after news of the attack, reversing a weakening trend that had accompanied the Leave campaign's surge.
'HORRIFIC MURDER'
"The whole of the Labour Party and Labour family - and indeed the whole country - will be in shock at the horrific murder of Jo Cox today," Labour leader Jeremy Corbyn said.
The last British lawmaker to have been killed in an attack was Ian Gow, who died after a bomb planted by the Irish Republican Army (IRA) exploded under his car at his home in southern England in 1990.
Police said a 77-year-old man was also assaulted in the incident and suffered injuries that were not life-threatening.
BBC TV and other media showed a picture of the alleged suspect, a balding white man, being apprehended by police. Temporary Chief Constable Collins said a "very significant investigation with large numbers of witnesses" was under way.
"We are not looking for anyone else in connection with this incident," she said.
Jayda Fransen, deputy leader of Britain First, suggested that "Britain first" was a common slogan being used in the referendum campaign by those who support taking Britain out of the EU.
"We were as shocked to hear these reports as everyone else," Fransen told Reuters. "At the moment would point out this is hearsay, we are keen to verify the comments but we can only do that when the police provide more details."
The last attack on a British legislator was in 2010, when Labour member and ex-cabinet minister Stephen Timms was stabbed in the stomach at his office in east London by a 21-year-old student who was angry over his backing for the 2003 Iraq war.
In 2000, a Liberal Democrat local councillor was murdered by a man with a samurai sword at the offices in western England of lawmaker Nigel Jones, who was also seriously hurt in the attack.
Cox, a Cambridge University graduate, spent a decade working in a variety of roles with aid agency Oxfam, including head of policy, head of humanitarian campaigning based in New York and head of its European office in Brussels.
She was known for her work on women's issues, and won election for Labour in northern England's Batley and Spen district at the 2015 general election.
Fellow lawmakers from several parties expressed their horror at the attack, praising Cox as a rising star of politics.
"She's a tiny woman, five feet nothing and a lion as well - she fights so hard for the things she believes in. I cannot believe anyone would do this to her," fellow Labour lawmaker Sarah Champion told BBC TV.