London: Both sides in the British referendum debate Thursday suspended campaigning after Labour lawmaker Jo Cox was shot and critically injured in her northern England constituency.
West Yorkshire police said a 52-year-old man was arrested after the attack in Birstall, near Leeds. Police said a man in his late 40s to early 50s also suffered slight injuries.
Police identified the victim as a woman in her 40s. The Labour Party confirmed that Cox, 41, had been hurt. She had been due to hold a meeting with constituents in Birstall on Thursday.
British Prime Minister David Cameron tweeted he was "very concerned about reports Jo Cox has been injured. Our thoughts and prayers are with Jo and her family."
He cancelled a planned speech in Gibraltar because of the shooting.
Lee Cain, a press official with the "leave" campaign that wants voters to take Britain out of the European Union in the June 23 referendum, said campaigning has been cut off and a statement will be made shortly.
The "remain" campaign tweeted that its campaign activities were being halted.
Both sides had been campaigning feverishly ahead of what is expected to be a close vote.
Britain's Press Association news agency quoted eyewitness Hithem Ben Abdallah as saying Cox got involved in a scuffle between two men in Birstall, 200 miles (320 kilometers) north of London.
Abdallah said one of the men was fighting with Cox and then a gun went off twice and "she fell between two cars and I came and saw her bleeding on the floor."
Shopkeeper Sanjeev Kumar told the BBC said he saw a woman lying on the ground "bleeding from the mouth and nose," with two women trying to help her.
After around 15 minutes, the shop owner said emergency services arrived and tended to her with a drip.
Cox was elected to the House of Commons only last year and represents a constituency in Yorkshire, northern England, for the main opposition Labour Party.
Cox has made finding a solution to the Syrian civil war a top priority and has been critical of Britain's reluctance to deepen its military involvement against Islamic State extremists as part of that effort.
In recent weeks she has been campaigning for Britain to remain in the European Union ahead of the country's June 23 referendum.
Labour leader Jeremy Corbyn said he was "utterly shocked by the news of the attack on Jo Cox. The thoughts of the whole Labour Party are with her and her family at this time."
Cox's assistant confirmed to the PA she had been attacked.
In the past two decades, two other British lawmakers have been attacked during their "surgeries," regular meetings where constituents can present concerns and complaints. A Labour legislator was stabbed in the stomach and injured in May 2010 by a female student radicalized by online sermons from an al-Qaida-linked preacher.
In 2000, Liberal Democrat lawmaker Nigel Jones and his aide Andrew Pennington were attacked by a man wielding a sword during such a meeting. Pennington was killed and Jones injured in the attack in Cheltenham, England....