A woman has been arrested on suspicion of murder after an elderly man died and three others were injured during a knife attack in a village Co-op in south Wales.
Eyewitnesses described seeing people fleeing the store on Tylacelyn Road, Pen Y Graig, Rhondda Valley, after a woman attacked four people with a knife.
A man and a woman were seen bleeding from wounds to the neck, according to shopworkers.
South Wales Police said a 29-year-old woman from Porth was being held at Merthyr Tydfil police station.
The South Wales force had also referred itself to the Independent Office for Police Conduct, but did not say why.
Witnesses described seeing the aftermath of the incident, which happened at about 1.45pm on Tuesday.
Ravi Raj, 35, manager at the Pen Y Graig post office, said: "There was a woman attacking four different people with a knife.
"I saw one of the men bleeding from his neck and one of the women from the side of the neck."
Another man is in a stable condition in hospital and two other people have suffered non life-threatening injuries.
Kenan Bastug, who was working in his brother's kebab shop, said a woman ran into their shop having been stabbed in the neck.
He told the PA news agency: "There was no blood but we could see like a one-and-a-half centimetre wound.
"She was shocked and didn't talk. She was crying. She was trying to stop the girl stabbing the guy, and then she got stabbed as well, I think. That's what she said.
"She had a badge on that said NHS. But I don't know whether she worked for the NHS or not."
Another witness, who was sitting in a car outside the Co-op, said she saw an injured man in a van next to her being attended to by medics.
"This was the man who had been stabbed repeatedly, they took him out of the van and placed him into the ambulance," she said.
Businesses in the village were told to lock their doors as armed police and ambulances arrived at the scene.
People spoke of their shock at the incident, in an area which has colourful banners draped along Tylacelyn Road in support of the NHS.
Events in the Rhondda this afternoon have shocked everyone locally. You can't get more normal and ordinary than the Coop in Penygraig. So this feels horrific and extraordinary. My heart goes out to those who've been directly affected and my thanks goes to the police and NHS.
— Chris Bryant (@RhonddaBryant) May 5, 2020
Rhondda MP Chris Bryant said: "You can't get more normal and ordinary than the Co-op in Pen Y Graig.
"So this feels horrific and extraordinary. My heart goes out to those who've been directly affected and my thanks goes to the police and NHS."
Leanne Wood, Plaid Cymru Assembly Member for Rhondda, said: "This is the shop that is my local grocery shop, it's the shop that my family use to do most of our shopping in.
"I know the staff there, I know most of the regular shoppers there and it's a high street that is different to no other in Wales.
"It's really shocking news. My heartfelt sympathy goes to all of those who are affected, all of those who have been harmed by the incident and their extended families.
"My thoughts are with the staff in the Co-op as well who must have been traumatised by events there this afternoon."
My community of Penygraig will be shocked by the news of a serious violent incident in our local shopping street earlier today. My sympathies go to all those affected, their families & the shop staff who must have been traumatised to witness such horror. pic.twitter.com/jcY7RMwCM6
— Leanne Wood 🏴 (@LeanneWood) May 5, 2020
Andrew Morgan, leader of Rhondda Cynon Taf County Borough Council, said: "My thoughts are with the families and friends of those involved in this awful incident."
Police were appealing for witnesses to come forward, as well as anyone who had mobile phone footage.
Detective Chief Inspector Mark O'Shea, leading the murder investigation, said: "This is a very tragic incident and one man has died and his family is being supported by specially trained police officers.
"Our thoughts and condolences remain with the victim's family at this very sad time.
"This incident will have understandably caused a lot of shock in the local community and I want to reassure residents that a full investigation has been launched.
"However, we are not looking for anyone else in connection with this incident."