Police in the Indian city of Mumbai say they expect to soon make a breakthrough in the investigation into last week's bombings which left nearly 180 dead.
Security has been stepped up after the attacks
No significant arrests have as yet been made although police have questioned hundreds of people, mostly Muslims.
India has accused militants based in Pakistan for helping in the attacks but Pakistan has rejected the suggestion.
India says the attack has made it difficult to sustain the peace process with Pakistan.
But it says it is still committed to it.
Mumbai police, in the meantime, are continuing with their investigation.
"It's premature to speak of information we have received but we are working on all possible leads," the city's police chief, AN Roy, is quoted as saying by the Associated Press.
"We believed the breakthrough will come soon."
Later on Monday, Indian President Abdul Kalam will travel to Mumbai.
On Tuesday, he will lead a two-minute period of silence as homage to the victims of the serial bombings, at 1825 (1255 GMT), the exact time the attacks began exactly a week ago.
On Sunday, Prime Minister Manmohan Singh said there had to be "firm commitment" that Pakistani territory was not used to support terrorist acts directed against India.
"But the commitment has to be backed by action on the ground," he told journalists while travelling to the G8 summit in St Petersburg.
Pakistan has rejected the allegations and says it is willing to help in the investigation.
Indian security officials have suggested that the Mumbai bombings bore the hallmarks of Lashkar-e-Toiba, a Kashmiri militant group operating from Pakistan.
But the Indian government has not directly accused the group, which has denied any responsibility.
A Muslim organisation banned in India, the Students' Islamic Movement (Simi), has also denied involvement in the attacks.
Sketches of three men wanted over the bombings have been published in the Indian media.
Nuclear rivals Pakistan and India began peace talks in January 2004.
They followed a prolonged period of tension after militants attacked the Indian parliament in December 2001. That attack led to both sides amassing troops along their border.
Although both sides have made some headway in improving travel and other ties between them, there has been little sign of progress in solving their core dispute over the divided territory of Kashmir, which both countries claim.