Eight men have been charged over the death of a US graduate found beaten on the Greek island of Zakynthos on 7 July, local media report.
Texas native Bakari Henderson, 22, was brutally attacked after he left a bar following a dispute, police said.
Six Serbian nationals, a 34-year-old Greek and a 32-year-old British national of Serbian descent were detained after CCTV footage emerged.
A seventh Serbian tourist is also being questioned, Greek news agency ANA said.
‘Always the peacemaker’
Mr Henderson suffered severe head injuries in the attack at the coastal resort of Laganas, and was pronounced dead after being taken to hospital.
Witnesses reportedly told police he angered one of the bouncers when he and his friends tried to take a selfie with a waitress.
Footage later obtained by the police shows Mr Henderson being attacked by a group of men outside a shop.
The suspects are accused of beating Mr Henderson and leaving him unconscious in the street.
Police have reportedly ruled out racism or nationalism as a motive for the attack.
Mr Henderson’s friend, Travis Jenkins, earlier told ABC News that it was unlike him to get into a street brawl.
“Bakari was not one to act aggressively like that,” Mr Jenkins said, adding: “He was always the one who was the peacemaker.”
Mr Henderson graduated last month from the University of Arizona with a degree in business finance and entrepreneurship.
His family said they were “devastated” by his death.
“Bakari loved spending time with family and friends, travelling and meeting new people,” a family statement said.
“He was a big thinker and enjoyed coming up with new business ventures. Bakari was an inspiration to all he met.”
The recent graduate was in Greece working on a photo shoot for a new clothing line, according to his family.
Mr Henderson’s family is working with the US state department to recover his body while a GoFundMe page to help the family with the costs involved in “bringing back the body of Bakari and all funeral expenses” has raised nearly $60,000 (£46,000) of its $80,000 target.