India on Sunday night summoned the senior-most British diplomat in Delhi and demanded an explanation over the complete "absence of security" after pro-Khalistan separatist elements pulled down the Indian flag at the Indian high commission in London during a protest.
In a strongly-worded statement, the ministry of external affairs said India finds "unacceptable" the indifference of the UK government to the security of Indian diplomatic premises and personnel in the UK.
The deputy chief of the UK high commission in Delhi was summoned to the MEA over the serious incident of pulling down of the flag as high commissioner Alex Ellis is travelling, sources said.
"The senior-most UK diplomat in New Delhi was summoned late evening today to convey India's strong protest at the actions taken by separatist and extremist elements against the Indian high commission in London earlier in the day," the MEA said.
"An explanation was demanded for the complete absence of the British security that allowed these elements to enter the high commission premises," it said.
The MEA said the diplomat was reminded of the basic obligations of the UK government under the Vienna Convention.
"India finds unacceptable the indifference of the UK government to the security of Indian diplomatic premises and personnel in the UK," the MEA said.
It sought immediate steps to identify, arrest and prosecute those involved in today's incident.
"It is expected that the UK Government would take immediate steps to identify, arrest and prosecute each one of those involved in today's incident, and put in place stringent measures to prevent the recurrence of such incidents," the MEA added.
In a tweet, Ellis said, "I condemn the disgraceful acts today against the people and premises of the @HCI_London - totally unacceptable."