Six teenagers have been arrested on suspicion of the murder of a Polish man in a possible hate crime.
Two Polish men were set upon outside a row of Harlow takeaway shops in what Essex Police believe to be an unprovoked attack on Saturday night.
A 40-year-old man from Harlow died of head injuries on Monday and a 43-year-old man, also from Harlow, was discharged from hospital after he was treated for suspected hand fractures and bruising to his stomach.
The men were targeted in The Stow in Harlow, Essex at around 11.35pm on Saturday.
Essex Police said one line of investigation was that it was a hate crime.
Senior investigating officer Detective Inspector Al Pitcher, of the Kent and Essex serious crime directorate, said: "This is now a murder investigation and our inquiries have quickly led to the arrest of five teenage boys.
"Following this vicious attack, a man has sadly lost his life and I urge anyone with information to contact us as soon as possible."
Police will be carrying out extra patrols in the area to provide reassurance to the community.
Four 15-year-old boys and one 16-year-old boy, all from Harlow, were arrested on Monday on suspicion of attempted murder and then further arrested on suspicion of murder.
All five have been released on police bail pending further inquiries until October 7. A sixth boy, a 15-year-old from Harlow, was arrested on Tuesday afternoon on suspicion of murder and is awaiting questioning.
Councillor Jon Clempner, leader of Harlow Council, said: "I am saddened and shocked by this brutal attack in our community.
"My heartfelt thoughts and sympathies go out to the families and friends affected by this meaningless attack.
"I know Harlow and its communities will support each other through this and that all our communities will stand together.
"We don't know the full circumstances of what motivated this attack but whatever the motives were they will never ever have a place in Harlow."
He added the authority was working with police to supporting the community and extra patrols were in place to provide reassurance.