Britain’s ambassador to Iran, Robert Macaire, was arrested on Saturday in Tehran, briefly detained, and then released.

Sky News journalist Haynes reported from Kiev, Ukraine, that according to her sources Mr Macaire “was arrested, briefly, and then released”.

The British embassy in Tehran has reduced staff levels but the ambassador and his team are still in the country. Ambassador Macaire has been in post since March 2018.

The Mirror reports that Iranian media Tasnim News Agency claimed that the 53-year-old diplomat had been accused of inciting protesters and was arrested outside of Amir Kabir University. Iranian media claimed he was detained for several hours before being released.

Sky News reports that the ambassador had been attending a vigil to the victims of flight 752, but that the event quickly evolved into a demonstration. As soon as Ambassador Macaire realised the tone of the event had changed, he left. On his way back to the embassy, Mr Macaire had gone to a barber’s for a haircut and that was when he was arrested, according to the report. He was held for two hours, and following calls between Tehran and London, the ambassador was released and is said to now be at home.

Foreign secretary Dominic Raab confirmed the reports, releasing a strong statement, saying: “The arrest of our ambassador in Tehran without grounds or explanation is a flagrant violation of international law.

“The Iranian government is at a crossroads moment. It can continue its march towards pariah status with all the political and economic isolation that entails or take steps to deescalate tensions and engage in a diplomatic path forward.”

The arrest came amidst protests in the Iranian capital after the country’s Revolutionary Guard admitted it had “unintentionally” shot down a commercial Ukrainian aeroplane, killing 176 passengers and crew. Three of the victims were British.

AFP reports that hundreds of students had gathered at Amir Kabir University to pay their respects to the dead, but the gathering escalated into a demonstration against the Iranian regime, with the young Iranians demanding the arrests of those responsible. Alleging a cover-up, they shouted slogans denouncing the “liars”, and the news agency reported that some tore down posters of Revolutionary Guard general Qasem Soleimani, who was taken out in a U.S. airstrike last week.

This week, President Donald Trump has called on Europe, Russia, and China to abandon the Iran nuclear deal.

“They must now break away from the remnants of the Iran deal -– or JCPOA –- and we must all work together toward making a deal with Iran that makes the world a safer and more peaceful place. We must also make a deal that allows Iran to thrive and prosper, and take advantage of its enormous untapped potential. Iran can be a great country,” President Trump said on Wednesday.

However, on Friday the EU doubled-down on its support for the accord.