(CNN) British politician Jo Cox, described as a rising star of the opposition Labour Party, has died as a result of her injuries from an attack in her constituency Thursday, police said.
The 41-year-old is the first British lawmaker to be killed in office since Conservative MP Ian Gow was assassinated by the IRA in 1990.
Cox was shot and stabbed in the street in Birstall, near Leeds in northern England, the Britain Press Association reported, citing eyewitnesses. She had just finished a regular public meeting with constituents.
A 52-year-old man was arrested shortly afterward close to the scene of the attack, said Dee Collins, Temporary Chief Constable of West Yorkshire Police. Weapons, including a firearm, were recovered, she said.
At 1.48 p.m. local time, less than an hour after the attack, Cox was pronounced dead by a doctor working with a paramedic crew.
The MP’s bereaved husband, Brendan Cox, said that her killing marked the “beginning of a new chapter in our lives.”
“More difficult, more painful, less joyful, less full of love,” he said.
“I and Jo’s friends and family are going to work every moment of our lives to love and nurture our kids and to fight against the hate that killed Jo.”
Witness: Attacker yelled ‘put Britain first’
Police have not commented on the circumstances surrounding the attack and a motive wasn’t immediately clear.
But a witness claimed that the assailant who attacked Cox was yelling “put Britain first,” the Press Association reported.
Clarke Rothwell, who runs a cafe near the murder scene, told the Press Association: “He was shouting ‘put Britain first.’ He shouted it about two or three times. He said it before he shot her and after he shot her.”
The gunman fired three shots, the final one at her head, he told the Press Association.
Another witness, Hichem Ben Abdallah, said the attacker kicked Cox as she lay on the ground until a bystander intervened and the attacker produced a gun and shot her, the Press Association reported.
“There was a guy who was being very brave and another guy with a white baseball cap who he was trying to control and the man in the baseball cap suddenly pulled a gun from his bag,” he said.
The gunman was wrestling with Cox “and then the gun went off twice,” Abdallah told the Press Association. “I came and saw her bleeding on the floor.”
Footage circulated of the suspect on the ground after being apprehended by uniformed police officers.
Tensions high ahead of referendum
Britain is one week away from a momentous public referendum on whether to stay or leave the European Union.
Passions have been running high and the political environment has become toxic, with MPs accused of lying and making up their arguments on both sides of the debate.
Cox, who was elected a member of Parliament for Batley and Spen in Yorkshire last year, was a supporter of Britain voting to remain in the EU.
Her husband and two young daughters were on a boat on the River Thames Wednesday as part of the Stronger In campaign, she tweeted at the time.
Campaign groups on both sides of the debate on next week’s referendum announced they were halting their operations Thursday in the wake of the attack.
Britain First, a fringe nationalist political party, issued a statement denying any connection in the attack in light of reports about the assailant’s comments. The statement said the party “would never encourage behaviour of this sort.”
Nation mourns
News of the killing has sent shock waves through Britain, where attacks on politicians are extremely rare and the slaying of a lawmaker is without parallel in recent history.
Vigils were held in Birstall and in Parliament Square, London, as people gathered to pay tribute to the murdered politician.
British Prime Minister David Cameron, who canceled a scheduled “Stronger In” pro-EU rally in Gibraltar Thursday following the attack, described the killing as “dreadful, dreadful news.”
“She had a huge heart. She was a very compassionate, caring MP. She was a bright star — no doubt about it. A star for her constituents, a star in parliament, and a star right across the House.”
Labour leader Jeremy Corbyn said the whole country would be in shock at the “horrific murder” of a politician he said was “universally liked at Westminster.”
“Jo Cox died doing her public duty at the heart of our democracy, listening to and representing the people she was elected to serve. It is a profoundly important cause for us all,” he said in a statement.