Yui Mok / PA Wire/Press Association Images
A woman lays some flowers at Parliament Square in tribute to Labour MP Jo Cox.
Vigils were held outside Parliament on Thursday evening after the shock news that Cox had died after being shot and stabbed during her surgery session where she opened her office to the public to ask for help and guidance. A man has been arrested in connection with the incident and been named locally as 52-year-old Tommy Mair.
Cox had been a Labour Party MP for Batley and Spen for just over a year and worked for Oxfam before running for Parliament. She was known for her work on Syrian refugees and was a passionate human rights campaigner.
Gordon Brown and his wife Sarah on Friday issued a tribute to Cox, who had worked with Sarah Brown in the past. Gordon calls Cox "the most vivacious, personable, dynamic and committed friend you could ever have," while Sarah says in her statement she is "heartbroken" and Cox had a "truly remarkable spirit and passion."
Cox is the first sitting MP to be killed since Conservative politician Ian Gow was killed by an IRA in 1990. Both sides of the upcoming EU membership referendum have suspended campaigning in the wake of the incident out of respect.
Here is what world leaders, friends, and colleagues have said about the shocking incident. All comments are from public statements unless stated otherwise from other sources: