TEHRAN (Dispatches) -- The diplomatic confrontation between Britain and Iran continued Monday as Iranian police released a video of the UK ambassador in Tehran shortly before his arrest and the Foreign Office summoned Iran’s ambassador to protest.
The short video shows Rob Macaire on the campus of the Amirkabir University where a group of people were chanting slogans against the Iranian authorities, allegedly in protest at the accidental downing of a Ukrainian airliner.
Iranian police said the video bolstered their case that Macaire had been inciting the rioters against the Islamic Republic.  
The British government had said that the ambassador had been attending a vigil for the 176 people killed on Flight PS572. Iranian security forces followed Macaire to a barber shop nearby and arrested him before releasing him several hours later.
Hamid Baeidinejad, Iran’s ambassador, has been called in for a meeting at the Foreign Office in London for ministers to convey their "strong objections” to the incident, Downing Street said.
On Monday, the Iranian media was abuzz with reports of British Ambassador Rob Macaire monitoring the protest from a safe distance. Macaire was briefly arrested by security forces over his presence at the site of a protest.
Government spokesman Rabiei said Britain’s ambassador to Iran had acted in a way that was "completely unprofessional and unacceptable”.
On Sunday, hundreds of angry protesters gathered outside the UK embassy to chant "Death to England” and demand the mission’s closure. Several Iranian politicians have called for Macaire to be expelled from the country.
Macaire was last week called in by the Iranian Foreign Ministry for an official dressing down over the way in which senior British politicians including Boris Johnson and UK Foreign Secretary Dominic Raab had appeared to welcome the U.S. assassination of General Soleimani.
The protest attended by Macaire featured the tearing up of the pictures of top Iranian commander Gen. Qassem Soleimani who was assassinated by the U.S. in Iraq.
The assassination triggered a wave of anger among the Iranians who took to the streets in tens of millions to call for revenge and honor the charismatic commander.
The insults against Gen. Soleimani shocked many Iranians and raised question marks about the instantaneous protest which came while the nation was mourning its national hero and celebrating Iran’s retaliation.
Many believe the downing of the jet is being used as a pretext to overshadow the epochal display of unity across Iran during Gen. Soleimani’s funeral and the country’s unprecedented blow to the American prestige through precision-guided missile at on U.S. bases.
Maple Leaf Foods Inc Chief Executive Officer Michael McCain on Sunday criticized the U.S. government for escalating tensions in the Middle East, after an Iranian missile accidentally shot down a Ukrainian airliner killing 176 people onboard, including an employee’s family.
"A MLF colleague of mine lost his wife and family this week to a needless, irresponsible series of events in Iran. U.S. government leaders unconstrained by checks/balances, concocted an ill-conceived plan to divert focus from political woes,” McCain said in a tweet posted on the company’s Twitter account.
Iran admitted on Saturday that it accidentally shot down the plane. Iran said its air defenses were fired in error while on alert after Iranian missile strikes on U.S. targets in Iraq.
Iran’s government on Monday denied a "cover-up” after it took 48 hours for the armed forces to admit the Ukrainian airliner was shot down by mistake last week.
"In these sorrowful days, many criticisms were directed at relevant officials and authorities... some officials were even accused of lying and a cover-up but, in all honesty, that was not the case,” Government spokesman Ali Rabiei said.
Iranian President Hassan Rouhani called the shooting down of the plane a "disastrous mistake”.