Willy Monteiro Duarte, 21, died after being beaten with kicks and punches in a brutal assault in Colleferro, a town south of Rome, in the early hours of Sunday, Italian news agency ANSA reported.

Duarte was reportedly attacked after he had attempted to save his friend from being beaten.

Four men in their 20s from the nearby town of Artena have been arrested on charges of manslaughter following Duarte’s death.

The four alleged suspects, currently detained in Rome’s Rebibbia prison, have been named as: brothers and mixed martial arts practitioners Gabriele and Marco Bianchi, aged 26 and 24; Francesco Belleggia, 23; and Mario Pincarelli, 22.

Already known to police and feared in their hometown for their propensity for violence, they have been described as the “Banda di Artena” (Artena Gang) by Rome newspaper Il Messaggero.

“Everyone knew those two brothers; they’ve been fighting and beating people in the same way for two years and they’ve committed other beatings,” one of Duarte’s friends, who identified himself as Alessandro, told ANSA.

Prosecutors are also investigating whether the attack was racially motivated, according to ANSA.

The four – who have maintained their innocence – were expected to be interrogated on Tuesday, while an autopsy will be carried out on Duarte’s body on Wednesday.

The beating took place at around 1:00 am on Sunday in the centre of Colleferro, however there were no security cameras in the area to capture the incident.

There are also varying accounts of the attack, which is still under investigation.

According to initial reports, Duarte had noticed his friend being threatened by another man and immediately stepped in between the two in an attempt to diffuse the situation.

However the aggressor made a phone call for “backup” and within minutes a black Audi Q7 pulled up and three friends men got out and beat Duarte “until he stopped breathing”, according to Italian daily La Repubblica.

The attackers allegedly fled the scene in the SUV driven by a fifth member of the gang, currently being questioned, according to Italian newspaper Il Fatto Quotidiano.

A local woman who witnessed the attack told La Repubblica:

“I will never forget the screams of that young boy.

“He said ‘enough, please, enough, I can’t breathe anymore’.

“Poor thing; those were devils, not human beings.”

Duarte, the son of a Cape Verdean couple who moved to Paliano many years ago and worked on a local farm, was born and raised in the small town in the province of Frosinone.

He had only recently become an Italian citizen.

He attended the hotel school in Fiuggi and worked as an assistant cook at the Hotel degli Amici di Artena.

He played in the local football team and was a big fan of AS Roma, which tweeted:

“Willy Monteiro Duarte dreamed of one day pulling on the Giallorossi shirt of his beloved #ASRoma. That dream ended last night, in the most tragic and brutal of circumstances. Our thoughts are now with Willy’s family and friends. Rest in peace, Romanista.”

The attack has caused widespread outrage in Italy, and several politicians have condemned the assailants.

On Monday, a day of mourning was declared in Colleferro as well as in Paliano, the nearby town where Duarte lived.

Lazio governor Nicola Zingaretti commented on Facebook: “Willy wanted to be a cook, today his mother tells us about it. We all mourn this generous young man, along with his friends and family. We will name a hotel institute in Lazio after Willy. For him, for his altruism, in his memory against violence.”

Zingaretti added that the Lazio Region will pay the legal fees in the proceedings for the young man’s death.

“We will not leave the family on their own,” he said.

The hotel where Duarte worked has also launched a fundraising campaign to assist his family financially.

Foreign Affairs Minister Luigi Di Maio posted: “You can’t die like that. At 21, killed by a bunch of thugs, beaten with kicks and punches. It’s not possible. Willy deserves justice and whoever killed him must pay an exemplary punishment.”

Meanwhile, the four under arrest have been subject to a torrent of insults and hatred on social media by people outraged over Duarte’s death, leading to the hashtag #vigliacchi (cowards) trending in Italy.

Duarte’s death comes at a time when tensions over racism are particularly acute following the death of George Floyd, an African American man who died while in police custody in May after an officer knelt on his neck for nearly nine minutes, despite pleas from Floyd that he could not breath.

The protests that erupted after Floyd’s death went international, with numerous groups taking to the streets to protest racism throughout Europe, including Italy, which has long been accused of espousing racist views, particularly towards migrants.