Pakistan President General Pervez Musharraf has rejected the indirect accusations made by India and said his country would fully cooperate in any investigation.
"The president has said we are ready to cooperate in the investigations," spokeswoman Tasnim Aslam said. "But evidence has to be shared with us.
"In the absence of that it will be just a claim. While pointing fingers on any Pakistan entity, they should also share evidence with us," The Indian Express reported on Tuesday.
"Pakistan stands with India on this act of terrorism which has been perpetrated in New Delhi."
Musharraf called Indian Prime Minister Manmohan Singh on Monday to express his condolences, and Singh told him that the investigation into the blasts indicated "external linkages of terrorist groups" with the attacks, said Sanjaya Baru, a spokesman for the Indian leader.
As part of the 10 minute phone call, Musharraf was quoted as saying the attacks "will not have any impact on the peace talks and on India-Pakistan relations. They should not have any impact", according to The Indian Express.
During Monday's call, Singh "drew [Musharraf's] attention to Pakistan's commitment to ending cross-border terrorism, and said that he continued to be disturbed and dismayed at indications of external linkages of terrorist groups with the 29 October bombing," Baru said.
The blasts came as Indians were
preparing for religious festivals
Pakistan's government was quick to condemn the bombings, and Musharraf called the New Delhi bombings "a dastardly terrorist attack".
A previously unheard of group has claimed responsibility for the Delhi bombings.A man called a local news agency, Kashmir News Agency, in Indian-administered Kashmir to say the Inquilab (Revolution) group staged the bombings.
The caller, who identified himself as Ahmed Yar Ghaznavi, said the bombings were "meant as a rebuff to the claims of Indian security forces" that Kashmiri fighters had been wiped out by Indian security crackdowns and the 8 October earthquake that devastated the mountains of Kashmir.
"Such attacks will continue until India pulls out all its troops from the state [of Kashmir] and stops inhuman activities in the state," Gaznavi was quoted as saying.
The claim has not been verified, and Indian police say they have no record of such a group existing.
Indian analysts and the media have, however, been quick to point the finger at some Kashmiri groups seeking independence.
Home Minister Shivraj Patil refused to comment on the claims but said: "We have lots of information but it is not proper to disclose it yet. Our people are making good progress. The investigation is going well."
"We have lots of information but it is not proper to disclose it yet"
Indian Home Minister
Police have in the meantime announced a reward of $2200 for any information that could lead to the arrest of those responsible for Saturday's bombings which left 59 people dead. The police have arrested a number of people.
Initial police reports put the death toll at 61 but was later reduced to 59 due to some bodies being counted twice, the Associated Press reported.
Sketches of suspects
Meanwhile, Indian police say they have uncovered a number of clues and are busy drawing sketches of two people they say are suspects. In one incident a man was seen asking a rickshaw vendor to wait at a stall leaving a bag behind which police say later exploded.
Police say they have gathered
vital clues from the scene
In the other incident, police say a bus passenger who raised the alarm in Govindpuri and whose identity has not been revealed, said he saw the bag and spoke to the suspect since the bag was obstructing foot space under the seat in front him.
Police are also scanning about 2 million mobile phone calls made between 4pm and 7pm on Saturday with one official saying that it seems mobile phones had not been used by those responsible prior to the blasts.
The attacks came at a sensitive time as India and Pakistan hashed out an agreement to partly open the militarised frontier that divides Kashmir to speed relief to victims of the region's 8 October earthquake.
The border deal was finalised early on Sunday.
Musharraf's remarks seemed intended to encourage momentum towards better bilateral relations between the rivals - who have fought three wars - after the earthquake, which killed an estimated 80,000 people in Kashmir.