A vigil is being staged later by Britain's Hindu community to remember nearly 200 people who died in the bomb attacks in Mumbai.
Prayers will be said for the victims
Mourners will gather to say prayers for the victims who died when explosives were placed on packed commuter trains during Tuesday's rush hour.
At least 181 people died and nearly 900 were injured.
Sunday's event, organised by the Hindu Council UK, takes place at 1500 BST at London Inter Faith Centre, Queens Park.
Indian police have rounded up 250 people as part of an intelligence operation, but named no suspects.
Senior officers said "many hundreds" had been picked up since the blasts, with most released after questioning.
There is growing pressure on police to make arrests over the case.
Investigators say the identity of the attackers remains "hazy" but the blasts bear the hallmarks of Lashkar-e-Taiba, an Islamist group active in Kashmir.
India said it would press leaders of the G8 summit in St Petersburg on Monday for greater co-operation in fighting terrorism in South Asia.
Prime Minister Manmohan Singh said the attackers had support from "elements across the border", widely seen as a reference to Pakistan.
He said the India-Pakistan peace process could not move forward unless "acts of terrorism" were brought under control.
Pakistan rejected Mr Singh's claims as "unsubstantiated" and said peace talks "must be continued and carried forward".
Islamabad also said it had taken action to rein in militants operating on its soil.