INVESTIGATORS are trying to establish the first definite link between the two teams of London bombers.

Since the second attacks on July 21, Scotland Yard has been trying to discover if alleged members of the two cells met.

There were reports from Pakistan yesterday that a terror suspect named as the alleged leader of the 21/7 group was in the country this year at the same time as two of the men killed in the suicide bombings on July 7.

Security sources in Islamabad are trying to establish whether Muktar Said-Ibrahim met two Yorkshire-born suicide bombers who were in the country at the same time.

Both Shehzad Tanweer and Mohammad Sidique Khan had family ties in Pakistan though relatives say they do not know where the pair stayed during their three-month trip this year. What interests police is where Mr Ibrahim visited, as the 27-year-old Eritrean refugee has no known family connections in Pakistan.

He is expected to be asked about his recent overseas travels during his continued questioning at Paddington Green high-security police station.

One senior security source said: “It could just be a coincidence or it could be a vital lead in establishing how these operations were planned, financed and executed.”

Until now the authorities have been careful about linking the two attacks. Police have yet to establish whether the strikes were planned and ordered by the same outfit.

While there are a number of obvious similarities between the synchronised attacks, Scotland Yard has yet to find hard evidence that the eight men allegedly involved were part of the same cell. They have all but discounted earlier suspicions that both groups met up on a whitewater rafting course in North Wales this year.

Forensic experts are still studying the explosives and other materials used in the bombings, but have not been able to come up with a definite conclusion.

The scientific investigation is taking longer than expected mainly because of the difficulty in recovering samples from the wreckage of the July 7 attacks that killed 56 people.

Detectives are still checking scores of telephone calls made by the two groups, and studying witness statements about possible sightings of individuals from both teams who were seen together. Intelligence experts have said from the start of this inquiry that their focus remains on Pakistan. They are still trying to discover who orchestrated the plan to paralyse London’s transport system with co-ordinated attacks on Tube trains and buses, as well as who built the bombs.

All four men involved in the July 7 attacks are known to have visited Pakistan. A number of them are understood to have attended madrassas there, and possibly training camps. What police are now concentrating on is attempting to discover whether there was a rendezvous between the suspected leaders of the “UK suicide cell” and the alleged head of the failed “East African” bombers.

Senior officials in Islamabad, quoted by NBC television, say that Mr Ibrahim flew into Pakistan from Jeddah, Saudi Arabia, last December.

Police and immigration officials in the kingdom have also been asked for their help to trace Mr Ibrahim’s movements while he was in the kingdom.

Counter-terror officers are still checking whether the two groups attended the same radical mosques here and abroad.

There are reports that Khan, who lived in Dewsbury, West Yorkshire, was a frequent visitor to the Finsbury Park mosque in North London.

Mr Ibrahim and others suspects from the 21/7 cell lived close to that mosque and are reported to have worshipped there together.

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