Turkeys Prime Minister Recep Tayyip Erdogan punched a man in a supermarket after visiting his town to commiserate with the victims of the country's worst mining disaster, eyewitnesses said.
The filmed incident, which happened a day after an accident that claimed the lives of around 300 people, cast further doubt on the Turkish leader's judgment after the emergence of separate footage showing one of his aides kicking a protester in Soma on the same day.
Opposition politicians said Taner Kuruca, the victim, worked as a miner for the company that owns the stricken mine.
Thursday's episode happened after Erdogan and several bodyguards sought refuge in the fruit and vegetable section of the Yesel Portakal supermarket in Soma, a few kilometres from the scene of the disaster, after a crowd of protesters began shouting abuse.
The Turkish leader, who eyewitnesses said looked angry, apparently lashed out at Kuruca thinking he was one of the protesters.
"The guy was just shopping, he had no relationship to the demonstration," said a woman. "I saw it all clearly. The Prime Minister seemed very angry with the man and was shouting something incoherently which I couldn't understand.
"The man looked totally shocked at being punched. The blow was really hard. Afterwards, I saw Erdogan's bodyguards kicking him and another man really hard in the groin."
As the woman was speaking outside the supermarket in Soma's main shopping thoroughfare, a group of men shouted "liar", "provocateur" and "don't misrepresent our country to others" at her.
Several employees of the supermarket claimed not to have seen the incident.
But another woman confirmed the account and said she would no longer vote for Erdogan.
We are all feeling great sadness here and our hearts are breaking, but rather than share our emotions he behaves like this. It would have been better if he hadn't come."
Kuruca told Turkey's Kanal D TV station that Erdogan had struck him "involuntarily" and said he would not press charges.
Erdal Semici, an official for the opposition National Movement Party, said he had been warned against speaking out by Erdogan's Justice and Development Party, which is said to be close to the mine's owners.