2018 attack on the Iranian Embassy in London
On 9 March 2018, supporters of Sadiq al-Shirazi affiliated with the Mahdi Servants Union attacked the Iranian Embassy in London. With the intention of supporting al-Shirazi's school and protesting the arrest of Hussein al-Shirazi by the Islamic Republic of Iran, these people entered the premises and balcony of the embassy, pulled down the Iranian flag and displayed the flag of their own group.
Source: Wikipedia — 2018 attack on the Iranian Embassy in London (CC BY-SA 4.0)