WEST Yorkshire MP Jo Cox has been reported shot and stabbed on the steps of Birstall Library, near Leeds.
Ms Cox, 41, is Labour MP for Batley and Spen. She won the seat in the 2015 general election.
Reports at the scene said the attacker – believed to be a man – remained at large.
Ms Cox was conducting a surgery at the library for constituents.
She is believed to have been airlifted to Leeds General Infirmary.
It is understood that other MPs in the area are considering closing their offices for the rest of the day as a precautionary measure.
There was speculation among some fellow MPs that Ms Cox may have been targeted over her failure to vote against air strikes in Syria.
A source close to Ms Cox said: “It’s just a massive shock. She has been a huge force for good for her constituency since she was elected.”
A police helicopter is hovering above the area.
Labour Chief Whip Rosie Winterton, the MP for Doncaster Central, is reported to have told colleagues that the incident is “serious”.
Witnesses said an onlooker tackled a man to the floor and tried to take a gun from him. Moments later, a second shot was heard.
An eyewitness said: “The whole scene has been taped off. There are armed police everywhere.”
One eye-witness told the Yorkshire Post: “I was just on my way to the Tesco in the middle of Birstall at about quarter past one when I realised a helicopter was in the air but didn’t think any more of it.
“Then as I got nearer to the library I heard a girl on her phone talking about a man with a gun and I saw the police tape and ambulances.
“It must have only just happened because there was at least one person still lying in the road being treated by paramedics.
“There was a big police presence and a few of them were armed, which was a bit unnerving to see so close to home.
“At about half one I saw a man being carried on a stretcher into an ambulance.