Azerbaijan on Friday summoned UK's charge d'affaires in Baku over Thursday's attack on the country's embassy in London.
A "resolute protest" was expressed to him in connection with the attack committed by a "religious radical group," said a statement by the Foreign Ministry.
The ministry underlined that the "provocation" seriously affects security of the diplomatic representation, urging the UK to take security measures in accordance with international legal obligations.
"Guarantees were requested from the opposite party that such situations would not happen again," it added.
A request was also made to conduct a thorough investigation by the relevant UK institutions, and bring the guilty to justice.
"The British chargé d'affaires expressed deep regret and concern over the incident," the statement read.
The embassy building in London was stormed by the Mahdi Servants Union, a Shia Muslim organization based in London, according to UK media reports. Eight people were arrested after police reached the area.
Elin Suleymanov, Azerbaijan's envoy in the UK, said on Twitter that the attack by "London-based radicals is unacceptable & barbaric."
"It directly undermined the principle of diplomatic premises' inviolability. I am currently in Baku & grateful to see that our colleagues are safe in spite of the threat to their safety & security," he said.