Labour MP Jo Cox has been shot in Birstall near Leeds and rushed to hospital in a critical condition.
A 52-year-old man has been arrested following the attack which left Ms Cox with serious injuries, police said. A man in his late 40s to early 50s nearby also suffered slight injuries
Ms Cox, former head of policy at Oxfam, was elected as the MP for Batley & Spen in Yorkshire last year.
The BBC reported that Ms Cox had been holding a constituency surgery when she was attacked, the first day of a parliamentary recess. She was flown to Leeds General Infirmary.
The Manchester Evening News reported that the attacker had shouted “Britain First” before the attack, according to an eyewitness. The man then walked away slowly.
Eyewitness Hithem Ben Abdallah, 56, was in the cafe next door to the library shortly after 1pm when he heard screaming and went outside.
He told the Press Association: “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.
He added: “He was fighting with her and wrestling with her and then the gun went off twice and then she fell between two cars and I came and saw her bleeding on the floor.”
After around 15 minutes, the shop owner said emergency services arrived and tended to her with a drip.
Ms Cox, 41, had grown up in the area, before becoming the first person in her family to graduate from university. On weeknights, she lives with her husband and two children on a traditional Dutch barge moored on the Thames near the Tower of London.
Fellow Labour MP John Mann said on Twitter, “Appalling news about the attack on Jo Cox in her constituency. Here’s hoping she is OK from me and all my constituents.” David Mackintosh, a Conservative MP, said: “Truly shocked to hear about Jo Cox, my Labour friend in Parliament. My thoughts and prayers are with her.”
A Labour spokesperson said, “We’re aware of the incident that happened this afternoon. All our thoughts are with Jo Cox and her family.”