Twenty people have been arrested after protesters outside the Indian embassy clashed with police, leaving one officer injured.
Hundreds of Sikh demonstrators blocked roads after gathering outside the building in Kingsway, central London, this afternoon.
Scotland Yard said the demonstration was initially peaceful but a “small group of protesters turned violent towards police”.
One officer was taken to hospital with a head injury, while the majority of arrests were for affray, the force added.
A Metropolitan Police spokesman said: “Whilst it was initially a peaceful protest the demonstrators blocked the roadway at the Aldwych and caused significant disruption to the central London road network.
“Police liaison officers attempted to negotiate with those present, in order to facilitate peaceful protest and minimise the disruption to the public.
“Additional officers, including those from the mounted branch, were mobilised to the area and a small group of protesters became violent towards police.
“During an altercation, one officer suffered a head injury and was taken to hospital. There are no reports of any of other injuries.
“At this stage police believe a number of offences may have been committed. There have been 20 arrests – the majority of which have been for affray.”
Scotland Yard said police had contained around 200 demonstrators shortly before 2.30pm.
According to the Sikh Press Association, the protest was part of the Sikh Lives Matters movement which has sought to raise awareness of alleged police brutality in India.
It said: “Recent deaths in Punjab have again brought to light the plight of ethnic minorities in India. Sikhs have continually found themselves victims of the most severe kind of police brutality, leading to the death of unarmed protesters and even bystanders during gatherings.
“However, there still seems to be a lack of empathy regarding the suffering of Sikhs.”