UK summons Iranian ambassador

Britain has summoned the Iranian ambassador to the country to convey its strong objections to the brief arrest of London’s envoy to Tehran, a spokesman for Prime Minister Boris Johnson said.

"This was an unacceptable breach of the Vienna Convention and it needs to be investigated," the spokesman said. 

"We are seeking full assurances from the Iranian government that this will never happen again.The FCO has summoned the Iranian ambassador today to convey our strong objections," Reuters cites him as saying.

British ambassador to Iran Rob Macaire was briefly detained on Saturday after attending a vigil for the victims of the Ukraine International Airlines disaster. He left the vigil when people began to demonstrate, but was later accused of helping to organize the protest.