As news broke that the same men reportedly planned the failed car bomb attacks in London and Glasgow, a second physician questioned in Australia over the U.K. terror incidents was released without charge, police said Wednesday.

The man was one of two doctors named by officials Tuesday as helping police with their inquiries into the failed terror attacks, according to the Associated Press.

"The man that was spoken to yesterday is now free to go. There is nothing there to charge that person," Police Commissioner Mick Keelty told the Australian Broadcasting Corp. radio.

Police arrested another doctor, Muhammad Haneef, 27, from India late Monday at the international airport in the Australian city of Brisbane, where he was trying to board a flight, the Australian attorney general said.

Meanwhile, Sky News reported the attempted bomb attacks on London's West End and Glasgow airport were allegedly carried out by the same men.

The two allegedly planted the car bombs in central London before heading to Scotland, Sky's Foreign Affairs editor, Tim Marshall, said.

"We have had it confirmed by sources that the two men who attempted to bomb London, it would appear, are the same two people who allegedly attempted to bomb Glasgow airport," said Marshall.

"In other words after that failed attempt they quickly went up to Glasgow and arranged this," he said.

Marshall said police were also already watching one of the eight arrested by police investigating the two bomb plots.

"The domestic security services were already aware of one of those arrested," he said.

Meanwhile, at least five physicians and a medical student were swept up in the fast-moving investigation, officials said, including a doctor seized at an Australian airport with a one-way ticket.

Many of the men had roots outside Britain — with ties to Iraq, Jordan and India — and worked together at hospitals in Scotland or England, officials said.

British Broadcasting Corp. and Sky News identified a suspect badly burned in the failed attack on Glasgow airport as Khalid Ahmed, also a doctor.

Police declined to confirm the identity, but had previously said the injured man was the driver of the Jeep that rammed the Scottish airport. He is hospitalized under armed guard.

At least four of the eight suspects were identified as doctors from Iraq, Jordan and India. One of the doctors from India, 27-year-old Muhammad Haneef, was arrested late Monday at the international airport in the Australian city of Brisbane, where he was trying to board a flight, the Australian attorney general said.

Staff at a Glasgow hospital confirmed that two of the others detained were a junior doctor and a medical student.

Mark Shone, a spokesman for Halton Hospital in England, said Haneef worked there in 2005 as a temporary doctor, coming in when needed. He also confirmed a 26-year-old man arrested in Liverpool late Saturday — also Indian — practiced at the hospital.

A 26-year-old suspect arrested in Liverpool also worked at the Halton Hospital, as well as the nearby Warrington Hospital, Shone said. He offered no other details.

Police in Glasgow said two men aged 25 and 28 were arrested Sunday in residences at the Royal Alexandra Hospital.

Staff at the hospital said one of the men was a junior doctor and the other was a medical student.

Amid increased security at British airports, train stations and on city streets, two men attempting to buy gas canisters at an industrial complex were arrested in Blackburn, northern England, under anti-terrorism laws. Police said it was too early to determine if the men were linked to the London and Glasgow attacks.

Amid increased security at British airports, train stations and on city streets, a bomb disposal team carried out a controlled explosion Tuesday on a suspicious car parked outside a mosque in Glasgow as a precaution.

On Saturday, two men rammed a Jeep Cherokee loaded with gas cylinders into the terminal at Glasgow's airport, then set the vehicle on fire. On Friday, two car bombs failed to explode in central London.

A British security official said Monday that Pakistan and several other nations were asked to check possible links with the suspects. British-born terrorists behind the bloody 2005 London transit bombings and others in thwarted plots here were linked to terror training camps and foreign radicals in Pakistan.

Authorities said police searched at least 19 locations as part of the "fast-moving investigation," which has come at a time of already high vigilance before the anniversary of the homicide bombings in London that killed 52 people on July 7, 2005.

The British government security official said investigators were working on one theory that the same people may have driven the explosives-laden cars into London and the blazing SUV in Glasgow.

The unidentified driver of the Jeep was being treated for serious burns at Royal Alexandra Hospital in Glasgow, where he was under arrest. Bomb experts carried out a second controlled explosion on a car at the hospital Monday, after a similar blast Sunday. Police said the car was linked to the investigation, but no explosives had been found.

Authorities identified Bilal Abdulla, an Iraqi doctor who worked at the Glasgow hospital, as the other man arrested at the airport. Staff at the Glasgow hospital said Abdulla was a diabetes specialist.

Haneef, 27, was being detained in Australia under counterterrorism laws that allow police to hold a suspect without charge as long as a judge agrees there are grounds to do so, Australian Federal Police Commissioner Mick Keelty said.

No charges were filed Tuesday, and Keelty stressed it had yet to determine what role — if any — Haneef had in the plots. Officials did not say where he was bound when he was detained.

"The doctor was regarded by the hospital as, in many senses, a model citizen — excellent references and so on," said Queensland Premier Peter Beattie.

A man arrested late Saturday on a highway in central England was also a physician, Mohammed Jamil Abdelqader Asha, police said. A Jordanian official said Asha was of Palestinian descent and carried a Jordanian passport.

Azmi Mahafzah, Asha's instructor at the University of Jordan medical school, said he knew Asha during his studies and training from 1998 to 2004.

"I didn't even have the impression that he was religious," he told The Associated Press. "He interacted with others, both boys and girls. He has no prejudices. He is not a fanatic type of person."

The family of Asha's wife, Marwa, who British officials said was with him in the car at the time of their arrest, denied she had links to terrorism.

"Marwa is a very educated person and she read many British novels to know England better, a country she liked so much," her father, Yunis Da'na told The Associated Press in Jordan.

None of the plotters arrested so far is named on U.S. terror watch lists that identify potential suspects, according to a senior U.S. counterterror official who spoke on condition of anonymity because of the sensitivity of the issue.

The Associated Press contributed to this report.