Police confirmed the altercation, saying: "Incidents involving animal rights activists at several restaurants in Brighton on Sunday evening, in which protesters with loudhailers chanted slogans at diners, have been reported to police."
"It was alleged that at one establishment a protester was punched by a customer, and at another activists were thrown to the ground.
"Currently no arrests have been made, but if criminal acts are found to have taken place, appropriate action will be taken."
The activist group made their own statement, saying: "'We must stand together against speciesism, but some are not ready to hear our message of equality and justice."
"Today, whilst bringing this message to diners at the chain restaurant, we were violently attacked. It is not surprising that those consuming violence are quick to partake in it too."
Vegan protesters from the same group hit the headlines in New Zealand recently when a group disrupted shoppers at supermarkets in Auckland and Hamilton.
In the Auckland incident, protesters clashed with shoppers with one angry customer telling the group: "Unless you're going to pay for my shopping you can f**k off."
DxE in New Zealand have promised to continue their campaign of disruption, saying the aim is to make people think and start a discussion.
"We wanted to go in and pay our respects to the victims in the chiller, while at the same time raising awareness to the general public – because in this day and age there is no reason to exploit animals for food," protest organiser Anna Rippon told the Herald.