A major thoroughfare next to Parliament has been blocked after Tamil supporters held another sit-down protest.
Around 2,000 gathered in a road opposite the Houses of Parliament, blocking vans and a bus. Scotland Yard said there had been no arrests.
Many of those on the demonstration wore a white cloth around their heads and arms as a sign of solidarity.
Military leaders in Sri Lanka say that they have crushed the Tamil Tigers’ 26-year insurgency.
They also claimed Tamil Tiger leader Velupillai Prabhakaran had been killed.
‘Deeply concerned’
Police helicopters circled above London’s Parliament Square and there was a large presence on the ground as traffic in the area was diverted.
There were no immediate plans to move the protesters, a police source said.
Many held flags and banners and there were a large number of children.
Pro-Tamil protesters have been demonstrating in Parliament Square for several weeks over the plight of Tamils in Sri Lanka.
Student Kulan Selvan, 32, from Catford, London, said: "I don’t know how long people are going to stay on the road but there is a strong feeling of real anger here.
"For us the war is not over and we simply do not believe reports that the Tamil leader has been killed.
Media access
"We are deeply concerned for the people in our homeland. We believe thousands have been killed.
"The Sri Lankan government have refused to let the media in so we just don’t know how bad it really is there."
He urged the media to give more prominent coverage to the conflicts in Sri Lanka.
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