The shocking moment a German student was fatally attacked for standing up for two underage girls during a fight at a McDonald's restaurant has been captured on camera.
Tugce Albayrak, 23, died on her birthday last week, after almost two weeks in a coma following a beating outside a fast-food restaurant in Offenbach, near Frankfurt.
The circumstances that led to her demise have shocked Germany, with thousands of people paying tribute to the university student and aspiring high school teacher.
Albayrak, who is of Turkish origin, was dining at a McDonald's on a Saturday night, when a violent quarrel, involving three young boys and two girls reportedly aged between 13 and 16, broke out in the restaurant's toilet area.
Friends said Albayrak left her table and stepped into the argument to try and restore calm after hearing the girls screaming for help.
The boys subsequently left the premises, but when the student came out about an hour later, they were waiting for her.
Security camera footage from a parking lot outside the restaurant shows the alleged attacker, identified only as Sanel M, 18, visibly enraged as he wanders around parked vehicles with another man who seemingly tries to calm him down.
As a group of people, including Albayrak approaches, Sanel M runs in their direction while the other man attempts to hold him back.
Albayrak confronts the man who appears hit her with a punch to the head. The woman falls, hits her head on the floor and stops moving.
The video was published by Bild newspaper with an appeal for witnesses to come forward with more information about the attack.
An Offenbach police spokesman said are seeking to speak with the two teenage girls who Albayrak reportedly tried to defend.
"We are still hoping that the two teenage girls will get in touch with us," said police spokesman Ingbert Zacharias.
Albayrak died on Friday last week, as her parents gave doctors permission to take her off life support after she was pronounced brain dead.
Hundreds of mourners attended candlelight vigils in her honour in Offenbach at the weekend.
An online petition for her to receive the Bundesverdienstkreuz (Federal Cross of Merit) has been signed by almost 140,000 people.
Sanel M has been arrested by police and remains in custody. Police said an autopsy is to be performed to determine the exact cause of Albayrak's death.
"I painfully miss my daughter and her smile," Albayrak's father Ali told Bild.
"We hope that her body will be released (by the authorities) Monday, so that we can bury her."