Investigations into who was behind the Bombay terror attacks focused last night on militant Islamic groups with links to Pakistan and its spy service.

As investigators searched a fishing vessel found adrift off the city’s coast with one dead body and a satellite phone aboard, a senior Indian official told The Times that the gunmen had sailed from Karachi, Pakistan. He accused a Pakistan-based militant group, Lashkar-e-Taiba, of carrying out the attack. Officials said that calls made from the phone on the boat had been traced back to Pakistan.

It is thought that the vessel was used by the terrorists before they climbed aboard a smaller boat to land at Colaba, the area that suffered the worst violence on Wednesday.

Yesterday Pranab Mukherjee, the Indian Foreign Minister, explicitly blamed Pakistani-linked “elements” for the carnage and Pakistan agreed to send its top military intelligence official to help with the investigation. It will be his first such visit to India.

Islamabad firmly denies that it had anything to do with the attacks, but officials do not rule out the possibility that outlawed militant groups based in Pakistan could have been involved. President Zardari said that “nonstate actors” were trying to disrupt his Government’s efforts to normalise relations with India and that they must not be allowed to succeed.

Indian officials are convinced that the attack on Bombay bears the hallmark of Lashkar-e-Taiba (LeT), linked to a suicidal attack on the Indian Parliament in 2001 which brought the neighbours to the brink of war. They also believe that LeT does not act without the sanction of some part of the Pakistan Government – though how far up the chain it leads is a matter of intense debate.

Abdullah Ghaznavi, a spokesman for the LeT, denied any role in the attacks and said that it had no links with any Indian group. “We do not believe in killing innocent civilians,” he said.

However, LeT has declared jihad against India, which it considers to be an enemy of Islam. A party document declared that the group is fighting to liberate Kashmir and reestablish Muslim rule in the whole of India. The group is said to have developed a strong network in India among radical Muslims.

The Pakistani military Inter Services Intelligence agency (ISI) has long cultivated Islamic militant groups such as LeT to fight its proxy wars in Kashmir and Afghanistan. But many of those militants have turned against their patrons after Pakistan joined the US War on Terror in 2001 and were involved in terrorist attacks that have plagued Pakistan.

India’s security forces are also investigating the possible involvement of Bombay’s most notorious mafia gang in the attacks – the network operated by Dawood Ibrahim, an organised-crime boss who ranks among the world’s top five most wanted men and is widely believed to have links with al-Qaeda.

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