Some 28 hours after their protest began, Tamils are still in Parliament Square in London. They say they will not leave until the UK government pledges to help stop the slaughter in Sri Lanka.
Over one thousand people have defied attempts to disperse them, mostly pecaefully but with some confrontations and six arrests.
Two of the arrests were for displaying images of the Tamil Tigers, an organisation banned in Britain under the Prevention of Terrorism Act.
However, the majority of the protesters want an end to violence on all sides, although they are especially critical of the Sinhala-majority Sri Lankan government, which they accuse of being responsible for the deaths of thousands of civilians.
Some of those who arrived in central London at 4pm yesterday have relatives in the country. They say the world and the European governments are turning a blind eye to the killing going on in their homeland.
The demonstration has already been successful in raising media and public awareness of what is going on, say organisers.
Meanwhile, a United Nations human rights expert warned today of a bloodbath in Sri Lanka unless government and rebel forces can stop fighting for long enough to allow tens of thousands of civilians trapped in the war zone to flee.
The civilians are in a precarious position, huddled in a narrow "no-fire" zone on the island's northeast coast where the rebels are holed up after a series of military defeats at the hands of government troops.
Walter Kaelin, an independent human rights expert appointed a representative of UN secretary general Ban Ki-moon, said: "It's absolutely necessary to avoid a bloodbath."
Talking to Geneva-based radio station WRS, he continued: "If the Sri Lankan army would try to go into there, if the LTTE would not be ready to let these civilians go, then we'll end up with a bloodbath, and this must by all means be avoided."
Following a four-day visit to Sri Lanka, Kaelin said he urgently called on the rebel movement , which has been accused of using Tamil civilians in the war zone as human shields, "to allow all civilians under its control to leave."
He also urged both sides in the conflict to pause the fighting "to allow civilians to leave" and allow aid workers "to provide life-saving relief to the remaining population."