Irish Olympian Jack Woolley has been injured following an incident in Dublin in the early hours of this morning.
The incident happened on Grattan Bridge at around 12.40am.
The Taekwondo athlete was brought to St James's Hospital for treatment.
The 22-year-old, who is from Jobstown in Tallaght, posted images of himself on social media before and after the incident, saying: "Literally two minutes between these photos".
In an update this afternoon, Mr Woolley thanked people for their messages of support.
He said he and a friend went out for a meal before heading to a bar.
While heading back along the boardwalk at the River Liffey, he said "a gang of roughly 8-12 men and women in their 20s began violently attacking people along the boardwalk.
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"Unfortunately I was victim to these random attacks as I was just walking by, before I was punched in the face by one of these group members."
Mr Woolley said he was punched only once, before being told "my mistake wrong person", as the group then ran off.
"Luckily I was able to phone an ambulance and stay conscious. My friends helped me throughout... and I’m glad to say they both are well and safe."
Gardaí say they attended the scene of an assault on Grattan Bridge and a man in his 20s was taken to hospital.
They said no arrests have been made and investigations are ongoing.
Mr Woolley was Ireland's first Olympian in taekwondo and was ranked eighth in the world going into this year's Games in Tokyo.
He lost his opening bout in the 58kg to Lucas Guzman of Argentina.
Following the incident, local TD John Lahart of Fianna Fáil has called for a greater garda presence in the city centre.
"This horrific and unprovoked attack on Jack Woolley is both sickening and deeply concerning. It's hard to believe that barely two weeks ago we were all wishing Jack well as he was Ireland’s first ever competitor in Taekwondo at an Olympic games, and now this terrible attack has happened.
"I am calling on senior garda figures to take a serious look at the current levels of garda personnel available to police our streets in the wake of this attack."