Three people, including a 16-year-old schoolboy, were stabbed to death in incidents across east London on Friday, the eve of the coronation.
The attacks, which are unconnected, took place in Walthamstow, Dagenham and Hackney over a period of eight hours.
The 16-year-old was ambushed after leaving Kelmscott School in Walthamstow. A local said his attackers were waiting for him, and he died in the street at 4.39pm.
No arrests have been made, and headteacher Sam Jones called the attack the “darkest of days” for the school community.
“A Kelmscott student was tragically killed in a senseless knife attack,” he said. “Kelmscott is a large and tight-knit family and this loss will be felt for a long time to come.
“Hold those that you love close this evening. I know we will come together as a community and support one another through this.”
An eyewitness said: “He was a year 11 kid. There were three other kids older than him. They were waiting for him.
“They chased him. He ran and when he got to the tyre shop they stabbed him three times in the stomach and he bled to death.”
Detectives have also started a murder investigation after a teenager was stabbed to death after two groups were reported fighting with machetes near Dagenham Heath Tube station.
Police and the London Ambulance Service were called shortly before midnight on Friday and found an 18-year-old man with stab injuries. He died at the scene despite the efforts of the emergency services.
A second man was taken to hospital with a stab injury, and a 20-year-old man was arrested on suspicion of murder and is in police custody.
Detective Chief Inspector James Shirley said: “My thoughts are with the young man’s family and friends.
“I want to offer my full reassurances to them, and the wider community, that despite the significant events taking place in London today, the focus of my team is bringing the person or people responsible to justice.”
Three people were also arrested on suspicion of murder after a man was fatally stabbed at a residential property on Mare Street, Hackney.
Police were called at 11.07pm on Friday and found a man in his late 20s, who was declared dead at the scene.
Two men, one in his 40s and the other in his 50s – and one woman in her 50s, have been arrested on suspicion of murder.
