LONDON — Myanmar’s ambassador to Britain, Kyaw Zwar Minn, was locked out of his own embassy on Wednesday, apparently in retaliation for criticizing the country’s military, which seized power in February and has since launched a bloody crackdown on pro-democracy protesters.

In a statement, Britain’s Foreign, Commonwealth and Development Office said that it was a “seeking further information” following the episode, which drew a small crowd of protesters outside the Myanmar Embassy in London.

“I have been locked out,” the ambassador told the Reuters news agency, calling the actions of diplomatic colleagues who prevented him from entering the building as a “kind of coup in the middle of London.”

Diplomatic sources confirmed that he had been excluded from the embassy and British media reports suggested that the ambassador’s deputy, Chit Win, had taken charge of the building with the help of a military attaché.