Protesters have clashed with police officers during demonstrations outside the Iranian embassy in London.
It comes as protests in Iran spread across the world, sparked by the death of Mahsa Amini in custody after being detained by Iranian morality police.
At least five officers were seriously injured, the Met Police said.
Twelve people have been arrested on suspicion of violent disorder offences.
Dozens of protesters in London chanted “death to the Islamic Republic” and were seen waving Iran’s pre-revolutionary national flag.
London mayor Sadiq Khan described the scenes as “completely unacceptable”.
“The selfish minority who attempted to hijack a peaceful protest must be brought to justice,” he said.
Footage posted online from Sunday’s protest showed scuffles breaking out among those in the crowd.
One clip showed two officers wrestling a campaigner – who appeared to have broken through the police line – to the ground.
Elsewhere, riot police could be seen trying to clear protesters off the road near Marble Arch.
The Met said the demonstrators had moved from the embassy towards Marble Arch and then to Maida Vale where the Islamic Centre of England was targeted.
Masonry, bottles and other projectiles were thrown and a number of officers were injured, the Met said. At least five people ended up in hospital with injuries including broken bones.
Police believed those taking part in the protest showed “substantial group intent on causing disorder”.
She was detained after being accused of violating the law requiring women to cover their hair with a hijab and their arms and legs with loose clothing.
There are reports that officers beat Ms Amini’s head with a baton and banged her head against one of their vehicles.
The police have denied that she was mistreated and said she suffered “sudden heart failure”. But her family has said the 22-year-old was fit and healthy.
Protests have taken place around the world in countries including Poland, Canada, Chile and Iraq.