New Delhi/IBNS: The National Investigation Agency (NIA) has arrested the key accused behind last year's attack on the High Commission of India in London and the protests that followed.

The accused, Inderpal Singh Gaba, a resident of Hounslow in the United Kingdom, has been arrested for unlawful activities during the March 22, 2023, protests.

The anti-terror agency said the attacks on the high commission were carried out in retaliation to the action taken by the Punjab Police against pro-Khalistani separatist Amritpal Singh on March 18 that year.

"NIA investigations in the case so far have revealed that the incidents in London on 19th March and 22nd March last year were parts of a larger conspiracy to unleash vicious attacks on the Indian missions and its officials," a statement from the NIA said.

On March 22 last year, pro-Khalistai supporters staged a protest at the Indian High Commission in London against the crackdown on Amritpal Singh.

They had pulled down the Indian flag from the building's first-floor balcony, prompting the Indian mission to put up an even bigger flag.

The Indian community in the UK had organised a large gathering in front of the Indian High Commission against the desecration of the Indian flag and demanded that the Mayor of London and the British government act against those responsible for the incident.

The Ministry of External Affairs had summoned the UK's seniormost diplomat in Delhi and demanded an explanation for the "absence of security" at the high commission. It had also said that the UK government's "indifference" to Indian diplomats and personnel was "unacceptable".