LONDON - Britain's investigation into last week's London suicide bombings widened on Friday with the arrest of a U.S.-trained Egyptian biochemist in Cairo and Pakistan probing links between one attacker and al Qaeda.
Egypt's Interior Ministry said 33-year-old Magdy Elnashar, a researcher at Leeds University in northern England, was being questioned in connection with the attacks that killed over 50 people and injured 700 on July 7.
He had left London for a 45-day holiday in Egypt before the bombings and had intended to return there, the ministry said in a statement. He had denied any knowledge of the attacks, in which four suicide bombers struck three underground trains and a double-decker bus.
An acquaintance of Elnashar said he was stunned the man he called "popular" might be involved in London's worst attack since World War Two.
British newspapers said he had rented a house in Leeds that was raided by police on Tuesday. Large amounts of suspected explosives were seized.
A spokeswoman for Leeds University said he was doing a doctorate in an environmentally friendly study involving "chemically-inactive substances" with implications for the food industry. He was sponsored in his studies by the Egyptian government.
Media reports said that in 2000 he had studied at North Carolina State University.
Al Qaeda Link
Separately, Pakistani intelligence sources said one of the attackers met in 2003 with a man later arrested for bombing a church in the Pakistani capital of Islamabad.
Pakistani security agencies are investigating possible links between militant groups based in Pakistan and Shehzad Tanweer, who blew himself up in a train near Aldgate underground station.
But a spokesman for one of the groups, a hardline Islamic charity organization called Jamaat-ud-Dawa, denied any links.
Three of the four bombers, including Tanweer, were British Muslims of ethnic Pakistani origin and lived in Leeds.
Police said 54 people were killed in the blasts, including two of the bombers. The other two bombers have yet to be formally identified.
In Leeds on Friday, Iqbal Sacranie, secretary-general of the Muslim Council of Britain called on Muslims, Jews and Christians to cooperate with the investigation.
Imam Shaykh Abdullah al-Judai told Friday prayers at Leeds Grand Mosque: "Prevent the recklessness of extremism, even if you have to inform the authorities. Such is the command of Islam.
"Islam considers this a crime which we condemn. No Muslim scholar has ever supported such acts through 14 centuries of Islam's history." London police chief Ian Blair said detectives were confident they would find a link between the British bombers and Osama bin Laden's al Qaeda group.
Warning that another attack is "a strong possibility", Blair said the hunt was on for the financiers and bomb makers who supplied the young killers.
"What we expect to find at some stage is that there is a clear al Qaeda link, a clear al Qaeda approach," he told BBC Radio.
The BBC, citing sources close to the investigation, said the explosive found in Leeds was TATP (triacetone triperoxide), made from freely available ingredients.
It said the material is thought to be similar to that used by British "shoe bomber" Richard Reid who tried to blow up a transatlantic flight in 2001 with explosives in his shoes.
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