A young Egyptian man, Karim Farghali, verbally attacked Muslim Brotherhood Supreme Guide Mohamed Badie late on Monday as the latter was having dinner with his family at a restaurant in the City Stars shopping mall in Cairo's Nasr City district.
Recounting the incident in a telephone interview with Egypt's Dream II satellite television channel, Farghali claimed that the argument arose when he asked Badie sarcastically: "Do you eat at an American restaurant because the US is backing your stay in power?"
Farghali said that he then told Badie: "Your end will be at our hands. Your days are few and you [the Brotherhood] will go back to jail."
According to Farghali, Badie replied to him "provocatively," saying: "God commissioned me not to reply to the likes of you."
The incident sparked pandemonium in the area, with some mall patrons reportedly chanting against Badie as he left the restaurant and walked through the mall.
Farghali denied claims that he had tried to assault Badie, asserting that his differences with the Brotherhood leader were merely political.
"We are well aware of who carries out assaults," Farghali added, in reference to recent political violence.
Brotherhood spokesman Ahmed Aref said it was the first time that the Supreme Guide had been attacked in such a manner.
According to Aref's account, Badie had replied: "If I'm the one who actually rules Egypt, then I agree with you: 'Down with the rule of the Supreme Guide'."
Aref said that Badie had attempted to talk with the angry man but that the latter had simply continued to repeat his chants against the Brotherhood leader.
Wahid Abdel-Meguid, spokesman for Egypt's Constituent Assembly (which drafted the country's recently-approved constitution) and currently a member of the opposition National Salvation Front umbrella group, condemned the incident and similar attacks on public figures.
"This growing public indignation is a reaction to the [government's] failure to contain the country's political malaise," Abdel-Meguid told Al-Ahram's Arabic-language news website on Tuesday.
Egypt has seen numerous demonstrations against the government since last summer, when Muslim Brotherhood candidate Mohamed Morsi won the country's first-ever free presidential election.