The UK's ambassador to Iran has been arrested during protests in Tehran after the country admitted that it shot down a passenger plane by mistake.

Photo: Atta KENARE / AFP

Rob Macaire was held for more than an hour, according to local media. The Foreign Office described his arrest as a "flagrant violation of international law".

Iran has now admitted Ukraine International Airlines flight PS752 was shot down due to "human error".

The Iranian Etemad newspaper shared a picture of the ambassador on Twitter after the Tasnim news agency reported his arrest during the protests outside a university.

Iranian media claimed Macaire was accused of inciting anti-government protests.

In a statement issued by Downing Street Foreign Secretary Dominic Raab said: "The arrest of our Ambassador in Tehran without grounds or explanation is a flagrant violation of international law.

"The Iranian government is at a cross-roads 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 forwards."

There were demonstrations in Tehran and other cities on Saturday as people gathered to commemorate those who died in the downing of the Ukrainian plane.

Missile strikes

Iran initially denied responsibility for Wednesday's crash - which killed 176 people, including four Britons.

But on Saturday, President Hassan Rouhani admitted Iranian military had "unintentionally" shot down the passenger plane after mistaking it for a cruise missile when it turned towards a sensitive military site.

President Rouhani said the missile strike was an "unforgivable mistake".

The crash came just hours after Iran carried out missile strikes on two airbases housing US forces in Iraq, amid heightened tensions in the region following the killing of Iranian general Qasem Soleimani on 3 January.

Tehran vowed revenge after he was killed in a drone strike ordered by US President Donald Trump.

- BBC