Protesters used loud speakers to call on the UK government to act to end the war in Sri Lanka on the second day of protests at Westminster which began on Monday afternoon.
Around 1,000 demonstrators occupied Parliament Square to wave flags and demand an immediate ceasefire in Sri Lanka.
Protesters displayed Tamil Tiger flags on statues, a group banned in the UK as a terrorist organisation. Sri Lanka's government has refused to pull back from its aim of wiping out the Tigers.
A young girl gets caught up in the rally which at times spilled over into minor scuffles with police. Some people needed medical attention for minor injuries.
Those at the rally say their friends and relatives are suffering at the hands of Sri Lankan government action. The UN says up to 150,000 civilians are trapped in the country's northern war zone.
There were minor clashes with police outside the Houses of Parliament. Police said officers were continuing to negotiate with protest leaders to "avoid having to make a huge number of arrests".
Some scuffles appeared to break out as police attempted to move the protesters, some forcibly. Officers had until then described the demonstration as peaceful.
A cordon of police officers kept the closed Westminster Bridge clear of people. There was also disruption to rush-hour traffic as some local roads were shut.
Hundreds of people remained at Westminster at nightfall on Monday including families with young children. Police allowed people to join the protest, despite a lack of advance notice making it illegal.
The noisy protest - involving chanting and banging drums - continued through the night. Those taking part pledged to remain until there was action over a ceasefire and said more protesters would arrive.