BERLIN (AFP) - Germans flocked to the funeral on Wednesday of a young woman of Turkish origin who has become a symbol of civic courage for giving her life while trying to protect two teenage girls.

Calls have mounted in mass online campaigns and in the German media for Tugce Albayrak, 23, to be posthumously awarded the Federal Order of Merit for her bravery in stepping in to help the teens being victimised in a fast-food restaurant altercation.

After confronting a group of men who were harrassing the girls last month, she received a blow to the head that sent her into a coma.

Her family switched off her life support system last Friday, her 23rd birthday, sparking a wave of sympathy in Germany, in both social and mainstream media, and widespread revulsion over the attack.

At Wednesday's funeral service, German and Turkish flags fluttered in the wind as around 1,000 mourners fell silent for prayers in a ceremony conducted according to Islamic rites and televised live on the NTV rolling news channel.

The premier of western Hesse state joined mourners bundled up warmly against icy temperatures for the service outside a mosque in the western town of Waechtersbach.

The coffin was then taken to a cemetery in nearby Bad Soden-Salmuenster, where Albayrak was born.

A surveillance video posted online by German Bild daily shows the Nov 15 incident in the car park in the town of Offenbach near Frankfurt.

It is unclear whether the young woman, an aspiring teacher, suffered the head injury from being struck by her attacker or in the subsequent fall.

An 18-year-old man is in custody and an investigation is under way.

Newspapers have hailed Albayrak as a role model in a country that is home to about three million people of Turkish origin, but which often struggles with its identity as a multicultural society.

President Joachim Gauck described Albayrak in a condolence letter to her family as having shown "courage in an exemplary way" and said she would always remain "a role model".

More than 165,000 people have signed an online petition for her to be awarded Germany's Order of Merit.

Chancellor Angela Merkel has "great sympathy" for the idea of presenting the award, her spokesman told reporters Wednesday but added it was up to the president to decide.

The tragedy has sparked a public outpouring of sympathy and shock, with a candle-lit vigil held Friday outside the hospital where she was treated.

Bild described her as a "hero" and said all of Germany was mourning the "brave" young woman "who stepped in when others only looked away".