LONDON - Police in Egypt today arrested an Egyptian biochemist who studied in the United States, and authorities investigated a possible link between al-Qaida and the suicide team that carried out the London bombings, officials said.

Magdy el-Nashar, 33, was arrested early today, the Egyptian official said, speaking on condition of anonymity because an official announcement of the information had not yet been made. El-Nashar, who studied at North Carolina State and Leeds University, was being interrogated by Egyptian authorities, the official said.

British and FBI officials were looking for el-Nashar, who recently had been teaching chemistry at Leeds University, north of London. The Times of London said el-Nashar was thought to have rented one of the homes police searched in Leeds in a series of raids Tuesday. Neighbors reported el-Nashar recently left Britain, saying he had a visa problem, the newspaper said.

Leeds University said el-Nashar arrived in October 2000 to do biochemical research, sponsored by the National Research Center in Cairo, Egypt. It said he earned a doctorate on May 6.

FBI agents in Raleigh, N.C., had joined the search for el-Nashar. North Carolina State spokesman Keith Nichols said a person named el-Nashar studied at the university as a graduate student in chemical engineering for a semester beginning in January 2000 until the spring.

Earlier, Metropolitan Police Commissioner Sir Ian Blair said investigators were hunting the organizers of the London transit attacks - perpetrated by what he called "foot soldiers" - and confirmed police were focusing on a Pakistan connection.

Three of the bombers who carried out last week's terror strikes were Britons of Pakistani origin. Pakistani intelligence officials said today that local authorities are looking into a connection between one of the three and two al-Qaida-linked militant groups in that country.

Blair told British Broadcasting Corp. radio that police believed they would discover an al-Qaida connection to the blasts that killed at least 54 people.