A long-serving member of Parliament has been stabbed to death during a meeting with constituents at a church in England, in an attack that has united Britain's fractious politicians in shock and sorrow.
A 25-year-old man was arrested at the scene.
Police gave no immediate details on the motive for the killing of 69-year-old Conservative lawmaker David Amess and did not identify the suspect, who was held on suspicion of murder.
The attack came five years after another MP, Jo Cox, was murdered by a far-right extremist in her small-town constituency, and it renewed concern about the risks politicians run as they go about their work representing voters.
British politicians generally are not given police protection when they meet with their constituents.
Essex Police said officers were called to reports of a stabbing in the town of Leigh-on-Sea just after noon and arrested a man and recovered a knife.
"We are not looking for anyone else in connection with the incident and do not believe there is an ongoing threat to the wider public," police said.
Sky News and other media said Amess was attacked during a regular meeting with constituents at a Methodist church in a residential section of the seaside city about 60 kilometres east of London.
Paramedics worked at the scene without success to save his life.Amess had been a member of Parliament for Southend West, which includes Leigh-on-Sea, since 1997, and had been a lawmaker since 1983, making him one of the longest-serving politicians in the House of Commons.
A traditional Conservative on the right of his party, he was a well-liked figure with a reputation for working hard for his constituents and campaigning ceaselessly to have Southend declared a city.
He was knighted by Queen Elizabeth II in 2015 for his service, becoming Sir David.
Politicians from across the political spectrum expressed shock and sorrow at the death of Amess, who leaves a wife and five children. Flags at Parliament were lowered to half-staff.
"This is an incident that will send shockwaves across the parliamentary community and the whole country," House of Commons Speaker Lindsay Hoyle said.
"In the coming days we will need to discuss and examine MPs' security and any measures to be taken, but for now, our thoughts and prayers are with David's family, friends and colleagues."
Violence against British politicians is rare, but concerns have grown in recent years about the increasingly bitter polarization of the country's politics.
In 2016, a week before the country's divisive Brexit referendum, Cox, a Labour Party lawmaker, was fatally stabbed and shot in her northern England constituency. An extremist was convicted.
Cox's widower, Brendan Cox, tweeted: "Attacking our elected representatives is an attack on democracy itself. There is no excuse, no justification. It is as cowardly as it gets."
British lawmakers are protected by armed police when they are inside Parliament, and security there was tightened after an attacker inspired by the Islamic State group fatally stabbed a police officer at the gates in 2017.
But politicians have no such protection in their constituencies. Amess published the times and locations of his open meetings with constituents on his website.
Former Prime Minister Theresa May, a Conservative, tweeted that Amess was a "decent man and respected Parliamentarian, killed in his own community while carrying out his public duties. A tragic day for our democracy."
Ex-Labour Prime Minister Tony Blair said he was "shocked and horrified."Two other British lawmakers have been attacked over the past two decades during their "surgeries," regular meetings where constituents can present concerns and complaints.
Labour legislator Stephen Timms was stabbed in the stomach in 2010 by a female student radicalized by online sermons from an al-Qaida-linked preacher.
In 2000, Liberal Democrat Nigel Jones and his aide Andrew Pennington were attacked by a man wielding a sword during such a meeting. Pennington was killed and Jones wounded in the attack in Cheltenham, England.
After the slaying, Conservative lawmaker Tracey Crouch tweeted: "Heartbroken. I could write reams on how Sir David was one of the kindest, most compassionate, well liked colleagues in Parliament. But I can't. I feel sick. I am lost."
Scottish First Minister Nicola Sturgeon of the Scottish National Party tweeted: "Elected representatives from across the political spectrum will be united in sadness and shock today. In a democracy, politicians must be accessible and open to scrutiny, but no one deserves to have their life taken while working for and representing their constituents."
Carrie Johnson, wife of Prime Minister Boris Johnson, wrote on Twitter that the news was "absolutely devastating".
"He was hugely kind and good. An enormous animal lover and a true gent," she said. "This is so completely unjust."Archbishop of Canterbury Justin Welby, head of the Church of England, said the killing was a blow to "everyone who desires a peaceful and flourishing democracy."