A foreign journalist was attacked on Sunday during a far-right protest in central Athens, the Greek news agency ANA reported.
The far-right was protesting the presence of migrants in Greece.
Thomas Jacobi, a correspondent working for the French newspaper La Croix and German broadcaster Deutsche Welle, was left bleeding in the face after the attack, according to an AFP reporter and a video broadcast by Skai TV.
"They were hitting me for four and a half minutes until some policemen appeared. No one stepped in. That's the most shocking thing," Jacobi told Greek media.
"I thought that with so many policemen there I could have done my job today. I was wrong again," he said, adding he felt lucky he was not attacked with a knife.
"They attacked me because they recognised me," Jacobi said.
It was the second assault on Jacobi, almost a year to the day since members of the Greek neo-Nazi party Golden Dawn attacked him, along with a cameraman and a photojournalist, also in Athens.
At the time, the three journalists were covering a protest outside the Greek parliament building over the renaming of North Macedonia.
Around 370 people, including Golden Dawn members, attended the protest at Syntagma Square on Saturday, according to the Greek police.
They held signs against the "colonisation of Greece by Islamists".
Jacobi said he will file a lawsuit, the Athens News Agency reported.
Jacobi has investigated Golden Dawn and worked with journalist Angelique Kourounis on a documentary on the topic, "The Golden Dawn: A Personal Affair", in 2016.
"Golden Dawners, no matter how hard you hit us, no matter if you are stealing our phones and recorders as you have done today, when 10 of you attacked us and especially Thomas, we won't back down. Our correspondences will be sent and the streets will be ours," Kourounis said in a tweet.
Greek government spokesman Stelios Petsas condemned "the fascist attack" on Jacobi and said the authorities were investigating.
The French newspaper La Croix published a short statement in support of Jacobi's, sending him "best wishes of recovery":
The Foreign Press Association of Greece (FPA) also condemned the attack and have asked the authorities to take action to identify the attackers.
"The existence of organised hit squads at the fringes of rallies aiming to intimidate journalists that are not of their liking can't be tolerated," the FPA said in a statement.
"We can only condemn" the attack, La Croix editor-in-chief Guillaume Goubert told AFP, adding: "We are worried."