Britain's Gordon Brown has ordered his new Security Minister Lord West to carry out an immediate review of the National Health Service in the wake of the attempted bomb attacks in London and Glasgow.
All eight people arrested in connection with the attacks have links to the NHS. Seven are believed to be doctors or trainee doctors while the one woman under arrest is a trained laboratory researcher.
A man arrested at Brisbane Airport on Monday was identified as Dr Mohammed Haneef (27), who once worked at hospitals in Cheshire. Another doctor questioned in Brisbane has been released without charge.
Addressing MPs at his first session of Prime Minister's Questions, Mr Brown said that the international watch list of potential terrorist suspects would be expanded so that authorities across the world can be warned.
And he announced further background checks for highly-skilled migrant workers entering the United Kingdom.
"It is vitally important that the message is sent out to the rest of the world that we will stand strong, steadfast and united in the face of terror," he said.
The Prime Minister said he would press ahead with the a Privy Council inquiry to look into the possible use of telephone tap evidence in terrorism cases.
"I hope that right across the House as right across the country there can be unity in our determination to fight terrorism," Mr Brown said.
Mr Brown said he was ready to look at Conservative proposals for a national border police force, and to consider a call from David Cameron for a ban on Muslim political party Hizb-ut-Tahrir.
Whitehall sources said that the Security Service had established "linkages" with a number of the individuals although it was not clear how much was known about them.
Nevertheless the sources said that MI5 had been able to pass on valuable information to the police which had helped to speed up their operation.
According to reports last night, the men involved in car bomb attempts in central London were also involved in the attack in Scotland on Saturday, when a Jeep Cherokee was driven into the arrivals hall at Glasgow airport.
The Joint Terrorism Analysis Centre will decide in the coming days whether there should be any lowering of the threat level - currently assessed as "critical", the most severe rating suggesting an attack is imminent.
It has emerged that some of the suspects detained following the Glasgow and London terror attacks had appeared on the MI5 database.