In recent weeks hundreds have demonstrated in front of the embassy in Knightsbridge to show solidarity with anti-government protesters in Iran.
The death of Mahsa Amini, 22, in September - after being detained by police in Tehran for allegedly not adhering to the Islamic dress code - triggered protests across the world.
Violence has broken out on several occasions outside the embassy in London, with dozens of protesters clashing with police as they call for an end to the Islamic Republic of Iran.
The Iranian Ministry of Foreign Affairs on Sunday summoned the British Ambassador to Tehran over an alleged ‘attack’ on the embassy in London.
The government deplores the actions of a “violent group” that led to the “disrespect of the Iranian national flag”, the state-run IRNA news agency reported.
IRNA said that the British ambassador was reminded of the country’s commitments in accordance with the 1961 and 1963 Vienna Conventions.
The Iranian Foreign Ministry also “strongly protested to the UK failure to prevent this sad attack”, they added.
The British ambassador reportedly expressed regret over the incident.
The protests have also spread to other countries, with Iranian demonstrators and activists raising slogans outside Iranian embassies in Athens, Berlin, Brussels, Istanbul, Madrid, New York and Paris, among other cities.
Twelve people were arrested and at least five officers “seriously injured” in clashes outside the Iranian embassy in London during the first wave of protests in September.