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.

Who was British MP Jo Cox?

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.

Jo Cox, 41, Labour MP for Batley and Spen, was left bleeding on the ground after the attack in West Yorkshire. A 52-year-old man was arrested nearby.

Her husband Brendan Cox said she would want people “to unite to fight against the hatred that killed her”.

Tributes flooded in from politicians including David Cameron, Jeremy Corbyn and US Secretary of State John Kerry.

Vote Leave and Remain have both suspended campaigning in the EU referendum in light of the attack.

Mrs Cox is the first sitting MP to be killed since 1990, when Ian Gow was the last in a string of politicians to die at the hands of Northern Irish terror groups.

Labour leader Mr Corbyn said the country would be “in shock at the horrific murder”, describing the MP as a “much loved colleague”.

He added: “Jo died doing her public duty at the heart of our democracy, listening to and representing the people she was elected to serve.

“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.”

‘People screaming’

Cafe owner Clarke Rothwell, who witnessed the attack, said he heard a “loud popping noise that sounded like a balloon burst – a loud balloon”.

“When I looked round there’s a man stood there in his 50s with a white baseball cap on and a jacket with a gun, an old fashioned looking gun in his hand,” he said.

“He shot this lady once and then he shot her again, he fell to the floor, leant over shot her once more in the face area.

“Somebody tried to grab him, wrestling with him and then he wielded a knife, like a hunting knife, just started lunging at her with a knife half a dozen times. People were screaming and running from the area”.

Eyewitness Hithem Ben Abdallah, said the mother of two was left lying and bleeding on the pavement after the incident.

Mr Abdallah, 56, was in a cafe next door to the library shortly after 13:00 BST when he heard screaming and went outside.

‘Handmade weapon’

“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”.

After a brief scuffle, he said the man stepped back and the MP became involved.

Mr Abdallah said the weapon had “looked handmade” and a man who had been wrestling with the gunman continued even after seeing the gun.

He said: “The man stepped back with the gun and fired it and then he fired a second shot, as he was firing he was looking down at the ground.”

“He was kicking her as she was lying on the floor”, he said.

Her husband, Brendan, has since tweeted a picture of his wife standing by the side of the River Thames in London.

David Cameron also tweeted to express his condolences.

Mr Kerry said: “It is an assault on everybody who cares about and has faith in democracy.”