India on Sunday summoned the United Kingdom’s senior-most diplomat in Delhi after a pro-Khalistan protestor pulled down the national flag at the Indian High Commission in London.

Visuals from the High Commission showed a protestor pulling down the tricolour, before a staff member secured the flag and handed it over to someone in the building. Other protestors were seen waving Khalistan flags and shouting slogans.

The protestors were demonstrating against a crackdown by security forces in Punjab against Sikh group Waris Punjab De – led by Khalistan supporter Amritpal Singh, The Hindu reported.

India’s Ministry of External Affairs on Sunday summoned British Deputy High Commissioner Christina Scott as High Commissioner Alex Ellis was not in New Delhi, PTI reported, citing unidentified officials. The ministry lodged India’s “strong protest” at actions taken by “separatist and extremist” elements in London.

“An explanation was demanded for the complete absence of the British security that allowed these elements to enter the high commission premises,” the external affairs ministry said. It added that New Delhi finds the “indifference of the UK government” towards the security of Indian diplomats and personnel unacceptable.

India urged the United Kingdom to take immediate action to identify, arrest and prosecute those involved in the incident, and take steps to prevent a repeat of it.

Foreign Office minister Tariq Ahmad said the government will take the security of the Indian High Commission seriously, adding that he was appalled by the vandalism.

Ellis said in a tweet that the incident at the Indian High Commission in London was “totally unacceptable”.

London mayor Sadiq Khan also criticised the vandalism at the mission, saying that “there is no place in our city for this kind of behaviour”.

Scotland Yard said that one man was arrested in connection with the pulling down of the Indian flag. It, however, said that most of those present had dispersed from the building before the police arrived.

The Metropolitan Police said that two security guards were injured and an investigation has been launched. “Windows were broken at the High Commission building,” the police added.

Over the weekend, 112 supporters of Singh have been arrested as part of statewide cordon-and-search operations against Waris Punjab De. Security forces are also attempting to take Singh into custody.

The 29-year-old had taken over Waris Punjab De last year before the death of its founder Deep Sidhu, an actor and activist who died in an accident in February 2022. Singh has garnered a large following in the state through his speeches that often focus on Sikhism and Punjab.

The state government has suspended mobile internet and SMS services till Monday afternoon.