The National Investigation Agency (NIA) will probe the case of protests and attempt to vandalise the Indian High Commission in London last month, officials said on Tuesday.

The NIA will take over the case from the special cell of the Delhi Police which had registered a case under the Unlawful Activities (Prevention) Act and the Prevention of Damage to Public Property Act as it involves unlawful activities carried out by certain people holding Indian nationality abroad.

According to officials, the NIA is mandated to probe any terror case that takes place in foreign land following amendments to the law governing the anti-terror probe organisation in 2019.

Pro-Khalistani protestors tried to vandalise the Indian High Commission in London and pulled down the national flag while holding protests outside the High Commission complex on March 19. It happened a day after the Punjab Police launched a crackdown against radical preacher Amritpal Singh in Punjab.

The Counter-Terrorism and Counter Radicalisation unit of the Ministry of Home Affairs handed over the case to the NIA and the decision was taken after Union Home Secretary Ajay Bhalla held a meeting with representatives of the British government last week.

In the London incident, the tricolour flying atop the Indian High Commission was grabbed at by a group of protesters waving separatist Khalistani flags and chanting pro-Khalistani slogans, leading to an arrest.

Officials from the mission said the "attempted but failed" attack had been foiled and that the tricolour was now flying "grander". The Metropolitan Police said two members of security staff sustained minor injuries which did not require hospital treatment.

India had summoned the British deputy high commissioner based in New Delhi and demanded an explanation over the complete "absence of security".

In a strongly-worded statement, the Ministry of External Affairs had said India finds "unacceptable" the indifference of the UK government to the security of Indian diplomatic premises and personnel.

Union Home Secretary Bhalla flagged the issue with a UK delegation which was led by Permanent Secretary, Home Office, Sir Matthew Rycroft and "specifically" conveyed New Delhi's concerns on the misuse of UK's asylum status by pro-Khalistani elements to abet terrorist activities and requested better cooperation, increased monitoring of extremists and take proactive action.

India's concerns over the breach of security at the Indian High Commission were also emphasised in that meeting.

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