An 18-year-old man was arrested on suspicion of setting off a flare and a 51-year-old woman was arrested on suspicion of criminal damage and assaulting a police officer, the Metropolitan Police said.
Scores of people gathered outside the store on Brompton Road, Knightsbridge, in a row over workers’ tips.
The road was partially blocked to traffic on Saturday afternoon.
Led by Unite Voices of the World union, demonstrators carried banners reading “Harrods stop stealing our tips”.
Doorways were blocked and smoke bombs set off as protestors demonstrated against the store’s service charge policy.
The union claimed in a post on Facebook that Harrods’s Qatari owner keeps up to 75% of the service charge, which can allegedly reduce the pay of its workers by up to £5,000 a year.
A post on the event page on Facebook reads: “Taking any percentage of the service charge, which customers think is going to the waiters, is unacceptable. Taking up to 75% is an utter disgrace.”
The union welcomed a pay rise which has been given to staff, but added that “chefs and waiters deserve 100% of the service charge”.
Concerns were also raised about those working at Harrods’ culinary department, with claims that waiters are on minimum wage and are “overworked”.
A Harrods spokeswoman said the company employs more than 450 people in its 16 restaurants “all of whom are paid fairly and above national living wage”, the Guardian reports.
“Harrods regularly revisits its policies to ensure that we best serve our employees and has been taking steps over recent months to review and improve the current system through which it distributes its service charge,” a spokeswoman said.
Harrods uses a “tronc” system, which automatically shares the service charge to its employees.