The First Minister has led tributes to Tory MP Sir David Amess who has died after being stabbed.
The Southend West MP was holding a surgery at the Belfairs Methodist Church, in Leigh, when a man ran into the church, according to the Southend Echo.
The newspaper reported Mr Amess was then stabbed "several times".
The 69-year-old had been a Member of Parliament since 1983, starting with Basildon before moving to Southend West in 1997.
Essex Police said a 25-year-old man was arrested on suspicion of murder and a knife was recovered from the scene - the force said it was not looking for anyone else in connection with the attack.
He was "treated by emergency services but, sadly, died at the scene", police added.
First Minister Mark Drakeford has sent his "thoughts and prayers" to Sir David and his family during this "distressing time."
He said it is a "truly despicable and horrifying act."
Leader of the Welsh Conservatives, Andrew RT Davies said Mr Amess represented his "constituents and our country with loyalty and dedication."
Plaid Cymru's leader Adam Prices said Mr Amess "was one of the kindest, most decent and deeply committed politicians I’ve ever known."
The Llywydd, Elin Jones MS, who has requested that all flags at the Senedd be lowered to half-mast, said elected members should be able to talk to the public "safely and without fear."
She said: “I’m deeply shocked and saddened by the death of Sir David Amess."
"Our democratic process depends on our elected members being able to listen and talk to the public we serve."
"It should go without saying that every elected member should be able to carry out this work safely and without fear."
"As Members, we may have different views, but we are always united in our respect for the democratic process and our commitment to serving the public," she said.
MP for Montgomeryshire Craig Williams said he was "heartbroken" and sent his love to his family, while MP for Clwyd West, David Jones said the news is "incomprehensible"
Labour MP for Ogmore Chris Elmore said Mr Amess "was as thrilled as I was" when he became a father earlier this year.
"His warmth was genuine and he couldn’t wait to share his excitement with me. I can’t comprehend David being killed, for doing the job I know he loved," Mr Elmore said.