Six teenagers in a town east of London have been released on bail after being arrested on suspicion of killing a Polish man in a suspected hate crime, British police said on Wednesday.

Police have reported a jump in hate crime in Britain after the country voted to leave the European Union in June, following a campaign that critics said stoked xenophobia and racism.

The 40-year-old man, named in local media reports as factory worker Arek Jozwik, suffered head injuries in a street attack in Harlow on Saturday and died in hospital on Monday evening, Essex Police said.

A second man, 43, was also attacked and suffered suspected fractures to his hands and bruising to his stomach. He has since been discharged from hospital.

Five boys aged 15 and one aged 16 were arrested on suspicion of murder, police said. One line of investigation was that the attack was a hate crime, they said.

The group has been released on bail until Oct. 7 pending further inquiries.

Poland's ambassador in London said in June he was "shocked and deeply concerned" about the reports of a rise in xenophobic abuse against the Polish community in Britain, which is estimated to number 850,000.