India has asked the UK to quickly arrest and prosecute those involved in pulling down the Indian flag at its mission in London on Sunday, Foreign Secretary Vinay Kwatra said on Monday.

Kwatra said that India lodged a strong protest and clearly indicated to the British authorities the need for putting up adequate security at the Indian high commission.

Later on the day, security was beefed up around the Indian High Commission in UK and Scotland Yard detained one person in connection with vandalism at the mission by Khalistan supporters a day earlier as India asked the UK to quickly arrest and prosecute those involved in the attack.

The national flag at the Indian high commission was pulled down during a protest by pro-Khalistan activists.

Following the incident, India summoned the senior-most British diplomat in Delhi and demanded an explanation over complete "absence of security" at the mission.

Kwatra, replying to a question at a media briefing, said the British deputy high commissioner was summoned and India demanded that the culprits and perpetrators of what happened in London on Sunday be quickly "arrested and prosecuted".

The foreign secretary referred to a statement issued on Sunday night by the Ministry of External Affairs (MEA) on the matter.

He, however, did not respond to a query on reports of pro-Khalistan protesters attacking the Indian Consulate in San Francisco.

Australian Prime Minister Anthony Albanese during his recent India visit assured his Indian counterpart Narendra Modi that Australia won’t tolerate any extreme actions like attacks on religious places.

Canada has also seen a rise in anti-India activities recently by Khalistan supporters who have vandalised some Hindu temples.

Last September, the Ministry of External Affairs issued a statement condemning the rise of hate crimes against Indians and anti-India activities in Canada, expressing their concern with stern language.