A 41-year-old British woman MP from the opposition Labour Party was was shot and stabbed to death on Thursday in her constituency in northern England by a man who shouted "Britain first", a week before the crucial referendum on UK's EU membership.
Labour MP Jo Cox was holding a meeting with constituents, in her local constituency when an altercation reportedly led to the attack.
Sky News television quoted unconfirmed reports that the shooter shouted "Britain first" -- possibly a reference to a far-right group of the same name.
Cox was rushed to Leeds General Infirmary, where armed police stood guard while medical experts tried to save her life inside.
Another man, in his 70s, was also injured in the attack and is also being treated for his wounds, which are said to be non-life threatening.
A West Yorkshire Police spokesperson said: "We are sad to confirm that Jo Cox died from the injuries she sustained in the attack."
"We urge any eyewitnesses who were in the area to come forward and help us with our inquiries to establish factually what exactly happened," the spokesperson added.
West Yorkshire Police confirmed a 52-year-old man has been arrested. Weapons, including a firearm, have been seized from the man.
"We are not looking for anyone else in relation to this tragic incident," the spokesperson said. The arrested man has been locally named as Tommy Mair but there is no confirmation on the motive or the exact nature of the attack, with some local witnesses describing hearing gun-shots while others saying it was a stabbing incident.
Sanjeev Kumar, an Indian-origin shopkeeper from the area, told BBC: "She was lying on the pavement and bleeding a lot. Someone had already called for an ambulance by the time I got to the scene".
The local community is to hold a vigil in Cox's memory at the local church in Birstall.
She is survived by her husband and two children.
Cox retained the Batley and Spen constituency for the Labour party in the 2015 General Election and has been in Parliament for just over a year.
She was due to celebrate her 42nd birthday next Wednesday and had been spoken of as a future minister for the Labour party due to her reputation as a strong politician and plain speaker.