A mass stabbing in a Reading park which killed three people and left three more seriously injured is not currently being treated as a terror attack, police say.
A 25-year-old man from the Berkshire town was arrested on suspicion of murder after the incident in Forbury Gardens at about 7pm on Saturday.
The alleged knifeman was "rugby tackled" to the ground by a hero police officer, a source said.
Heavily-armed and masked police officers were later seen at a block of flats in Reading after Saturday evening's attack, with a controlled explosion heard from inside by onlookers as residents were evacuated.
A shaken witness told Mirror Online the knifeman "shouted some unintelligible words" and stabbed victims in the neck and under their arms as the horrific mass stabbing unfolded.
It was initially reported that the attack was terror-related, but police have since said they are not treating it as a terrorism incident although they are keeping an open mind.
A source told the Sunday Mirror that a hero police officer saw a suspect running away with a knife and "rugby tackled him to the ground".
Prime Minister Boris Johnson said his thoughts were with those affected by the "appalling" incident, and Home Secretary Priti Patel said she was "deeply concerned" following the incident. It is understood Ms Patel is being kept updated on the situation.
Two people with stab wounds were rushed to the Royal Berkshire Hospital and were being treated in the emergency department. Two air ambulances landed at the scene and armed officers and a police helicopter were among the large presence.
A source told the Sunday Mirror: "A man pulled a knife and started attacking people at random in Reading, near the Crown Court. It is thought there was one attacker.
"It appeared the attack was stopped when a lone sergeant, who responded when the alarm was raised, ran to the scene, saw the attacker running away with a knife and rugby tackled him to the ground."
Detective Chief Superintendent Ian Hunter, Head of Crime, said: "The Thames Valley Police Major Crime Unit has launched a murder investigation following this incident.
"We have made one arrest and at this stage we are not looking for any other people in connection with this incident. There is no intelligence to suggest that there is any further danger to the public, however we urge people to remain vigilant and report anything suspicious by calling police."
A spokesperson for the local force said: "The thoughts of everyone at Thames Valley Police are with those who have been affected by this tragic incident and I understand the concern that this will have caused amongst the community.
"Please be assured that safety of the public is our primary concern and we will do all that we can to investigate this incident robustly and bring those responsible to justice."
"Anyone with information on what happened in Forbury Gardens should call Thames Valley Police on 101, quoting reference 1159 20/6."
