GLASGOW, Scotland — Doctors from Iraq and Jordan were among the eight suspects arrested in the failed car bombings in London and at Glasgow’s airport, officials said today. A witness said police were closing in on the terror network minutes before attackers rammed the Scottish terminal building.

Home Secretary Jacqui Smith said at least 19 locations were searched as part of the “fast-moving investigation.”

Late today, police announced the arrest of an eighth suspect, a man, in the failed attacks. Authorities would not disclose where the arrest was made, but the British Broadcasting Corp. reported the man was detained overseas. Seven others, including a woman, were arrested earlier.

Vigilance was already high less than a week before the anniversary of the deadly July 7, 2005, London transit bombing. Those were largely carried out by local Muslims, exacerbating ethnic tensions in Britain.

In the latest attacks, two car bombs failed to explode in central London on Friday and two men rammed a Jeep Cherokee loaded with gas cylinders into the entrance of Glasgow International Airport on Saturday.

The unidentified driver of the Jeep, which burst into flames, is being treated for serious burns at Paisley’s Royal Alexandra Hospital in Glasgow, where he is under arrest by armed police and where the Iraqi doctor reportedly worked. A 27-year-old man also was arrested at the airport and was being held at a high-security police station in Glasgow.

Police said one man arrested in Glasgow is Bilal Abdulla.

According to the British General Medical Council’s register, a man named Bilal Talal Abdul Samad Abdulla was registered in 2004 and trained in Baghdad. Staff at Royal Alexandra Hospital said one suspect was a doctor of Middle Eastern or Iraqi origin who worked there.

A second man arrested late Saturday on a highway in central England is Mohammed Jamil Abdelqader Asha, according to a police official who was not authorized to publicly disclose the details and spoke on condition of anonymity.

A Jordanian official said British authorities had contacted the Jordanian Embassy in London to say Mr. Asha, who reportedly worked at a hospital in central England, was a possible suspect. The official said Mr. Asha was a native Palestinian who carried a Jordanian passport.

In Jordan, Mr. Asha’s brother Ahmed told The Associated Press he had heard the media reports and said his 26-year-old sibling “is not a Muslim extremist, and he’s not a fanatic.”

“It’s nonsense because he has no terror connections,” he said.

Daniel Gardiner, a rental agent whose company leased a Glasgow-area home searched by police, said authorities contacted his firm 10 minutes before the airport attack, saying they had tracked phone records from it linked to the foiled London car bomb attacks.

“A card was put through one of my colleague’s door, asking if we would contact them,” he said.

“A couple of hours later, they (police) came back to us with a name, and we were able to trace their records,” he said. “The police wanted to know why we had dialed a certain phone number. They had the phone records from the situation down in London.”

Ian Thomson, who lives on the quiet suburban street, said the people who lived in the house kept irregular hours: “I would see at least one of them with a stethoscope and just assumed they were doctors working shifts.”

Gardiner said his tenant — the only person listed as living in the house — was thought to be a doctor at the Royal Alexandra Hospital. Bomb experts carried out two controlled explosions on a car at the hospital yesterday and today, Strathclyde Police said. Police said the car was linked to the investigation but that no explosives were found.

A British government security official said a loose Britain-wide network appeared to be behind the London and Glasgow attacks, but investigators were struggling to pin down suspects’ identities.

Security in London was highly visible this morning, with long lines of cars forming behind police checkpoints on London Bridge. Concrete slabs were in place protecting the Wimbledon tennis tournament.

In a statement to the House of Commons, Ms. Smith urged Britons to remain united.

“Let us be clear: terrorists are criminals, whose victims come from all walks of life, communities and religious backgrounds,” she said. “Terrorists attack the values that are shared by all law-abiding citizens.

“It is through our unity that the terrorists will eventually be defeated.”