Sources in the crime branch said on Tuesday that the police were zeroing in on three suspectstwo men and a womanon the basis of sketches based on eye-witness accounts and pictures clicked by a photographer at the Gateway of India before the blast.

The pictures showed the taxi in which the bomb was hidden and a few men standing near it.

The police claim the blast suspects are associates of Jaish members arrested in Thane last year. The Thane police had recovered documents showing maps of vital installations and tourist spots, including the Gateway of India, where Jaish members were planning to carry out major blasts.

Police teams have been sent to Gujarat, Bihar and several parts of Maharashtra to hunt for the suspects. However, the police have no clue about the passengers of the taxi involved in the Mumbadevi blast as the driver was killed in the explosion.

The crime branch is also probing the possibility of the Jaishheaded by Masood Azhar, one of the three militants released during the Kandahar hostage swap in 1999being assisted by the Lashkar-e-Toiba to carry out the twin blasts,which involved the use of tri-nitro toulene (TNT) and electronic timers.

"The two are Pakistan-sponsored terrorist groups and they share a common objective of destabilising India's economy and causing panic," an IPS officer said.

External affairs minister Yashwant Sinha also said that Mumbai was targeted "because what these terrorists and their sponsors envy the most is India's success in the economic field". He was speaking at the Institute of Defence and Strategic Studies in Singapore.

PTI from Islamabad: Urging Indian leaders not to resort to finger pointing in response to the bomb blasts in Mumbai, Pakistan on Tuesday denied Deputy Prime Minister L K Advani's charge that it has harboured Indians wanted for acts of terrorism in India.

"We have not given any shelter to any Indian nationals," Pakistan Foreign Office spokesman Masood Khan told the BBC while reacting to Advani's remarks made in Mumbai on Tuesday.

"I would like to add that this is not the time for finger pointing. Nor should Indian leaders take political mileage out of the gruesome tragedy. We condemn this reprehensible acts of terrorism," he said.

Asked why Pakistan did not co-operate with India in view of the recent thaw in the relations, he said, "yes there is a thaw. We should maintain the momentum generated. Therefore leaders in India should avoid making negative statements. These are unhelpful." "Yes this was gruesome tragedy. We have condemned it," he added.

Referring to Advani's charge that Pakistan's condemnation was a mere formality, Khan said Pakistan yesterday condemned the blasts with all sincerity because Islamabad was against terrorism in all its forms. "We are surprised by statement attributed to Deputy Prime Minister that our condemnation is not a mere formality as he characterised."

"Despite his negative reaction, we still sympathise and condole with the families of innocent civilians in Mumbai who have lost their lives and suffered injuries," he said.

Khan issued a statement later saying India has not provided any evidence of presence of Indian suspects in Pakistan. "Besides rejecting Pakistan's offer to investigate the acts of terrorism in India in the past, India has so far not provided any evidence about the presence of Indian suspects in Pakistan," the statement said. "Pakistan has already made it clear that the suspects are not on its soil."