Investigations are continuing after a 16-year-old girl died and two men were hurt in an incident in Rhondda Cynon Taf.
South Wales Police closed off Baglan Street, Treorchy, after reports of a stabbing at about midday on Friday.
Ambulance crews were also called in to deal with a number of casualties.
The public has been urged by police to “refrain from speculation” about the incident. Local MP Chris Bryant tweeted he was aware of “disturbing events”.
The two men have been arrested after suffering serious injuries.
South Wales Police said those involved were known to each other and no-one else was being sought over the matter.
The girl’s family is being supported by specially trained officers and efforts are being made to contact other relatives.
The police cordon was erected around a takeaway restaurant called Blue Sky, with a small white tent placed outside the premises.
Resident Sarah Belgrove, 54, who lives a few doors from the scene, said the air ambulance was forced to land some way from Baglan Street.
“The paramedics who got out of the helicopter flagged down some cars to give them a lift to the to the scene,” she said.
The Welsh Ambulance Service said it was called to an “incident at an address in the Ynyswen area of of Treorchy” at 12:00 GMT.
“We attended the scene with one rapid response vehicle, three emergency ambulances, our hazardous area response team and the Wales Air Ambulance,” said a spokesperson.
Supt Rich Jones, from South Wales Police, said there would be a “significant police presence in Baglan Street over the weekend” as investigations continued.
Rhondda MP Mr Bryant said lots of people knew the girl and her family and would be “absolutely devastated”.
“You don’t think of these kind of events happening in the Rhondda,” he told BBC Radio Wales Breakfast.