GLASGOW, Scotland — GLASGOW, Scotland -- Investigators have identified two "principal protagonists" in the botched attacks in London and Glasgow and are trying to establish how the other detained suspects fit in, a British security official said yesterday.
The two principal suspects are almost certainly the two men arrested after crashing their Jeep Cherokee into a terminal at Glasgow's international airport: Dr. Bilal Abdulla, a British-born Iraqi doctor who was formally charged yesterday, and a man known both as Kaleef and Khalid Ahmed, an Indian engineer who is being treated for severe burns sustained in the attack last week.
The British official, speaking on the condition of anonymity per British custom, suggested that it was becoming clearer that the other suspects - five men and one woman, all medical personnel - played a lesser role. Now, he said, "it's a matter of trying to fill in the gaps, to back-fill the gaps."
Yesterday, Abdulla, a 27-year-old Sunni described by acquaintances as angry over the U.S. and British presence in Iraq and over the increasing power of Shiites there, appeared in criminal court in London wearing a white T-shirt and was charged with conspiring "to cause explosions" endangering many people.
The first attempted attack involved two cars, both loaded with gas canisters, gasoline and nails in central London in the early hours of June 29. The second was at the airport a day later.
Investigators are trying to establish whether the al-Qaida network was involved, either from abroad or at home. They are also looking for what would motivate people in top professions to turn toward terrorism.
Details about the case have been trickling out over the past week, but critical questions linger about how many concrete links there are between the two men and the half-dozen others detained in the case. Questions also remain about the planning behind the two attacks, including whether they originated in Britain, Iraq or elsewhere, and whether any further attacks were intended.
The British police and intelligence agencies are urgently trying to pin down answers. Both MI5, the domestic service, and MI6, which sends spies overseas to gather information, are involved, the British security official said.
One of the other six suspects is a brother of Ahmed, according to a regional police chief in India whose force has interviewed their mother and other relatives. The police chief, K.R. Srinivasan, director general of police in Karnataka state, confirmed that Dr. Sabeel Ahmed, 26, who was arrested in Liverpool, was Kaleef Ahmed's brother. He also said that the mother had confirmed that Kaleef was the driver of the vehicle that slammed into the Glasgow airport.
He said that Indian investigators believed they were distantly related to the suspect arrested in Australia, Dr. Mohammed Haneef, 27.
But connections to the others are less clear. Mohammed Asha, a 26-year-old Saudi-born Jordanian of Palestinian descent, was seized along with his wife on the M6 highway in northwestern England a week ago. He had worked at a hospital in North Staffordshire as a junior neurologist; she was a laboratory technician.
Two other suspects who have not been identified, junior doctors possibly from Saudi Arabia, were working at the same hospital as Abdulla, the Royal Alexandra Hospital near Glasgow. But what further link they may have is unclear.
Some of the names were in MI5 databases, the security official said, though not as people who merited surveillance because of active involvement in a live terrorism conspiracy. The fact that they had been identified in the past - but not placed under surveillance - was taken as a sign that the suspects did not constitute a completely unknown set of radicalized people who had slipped through the net altogether, the official said.
Yesterday, London marked the anniversary of the July 7, 2005, bombings with a simple and somber ceremony outside King's Cross rail and subway station on one of the busiest tourist weekends of the summer, with the first leg of the Tour de France, the Wimbledon women's final and the Live Earth concert all under way. Prime Minister Gordon Brown and other government ministers joined survivors and relatives of the dead in laying bouquets and wreaths of flowers at a memorial garden to the victims. More than 700 people were injured in the rush-hour attacks on three subway trains and a double-decker bus. London Mayor Ken Livingstone left flowers and a card reading: "The bombers tried to divide us and they failed."
The Associated Press contributed to this article.