Brussels had no alarm, but it became one for many other international hot-spots across the globe.
Following the twin explosions at Brussels Airport on Tuesday in which more than 30 were killed, several countries have tightened or reviewed airport security.
While many world leaders condemned the bombings and expressed their solidarity with Belgium, Australian Prime Minister Malcolm Turnbull on Wednesday blamed Europe’s porous borders and lax security for the attack.
Islamic State claimed responsibility for the bomb attacks in the departure hall of Zaventem airport, and a rush-hour metro train, killing more than 30.
Prosecutors said the blasts at the airport, which serves more than 23 million passengers a year, were believed to be caused by suicide bombers.
Turnbull waded into the global debate about protecting borders, reassuring Australians that “our domestic security arrangements are much stronger than they are in Europe where regrettably they allowed things to slip”.
“That weakness in European security is not unrelated to the problems they’ve been having in recent times,” he said in Sydney.
Authorities in London, Paris and Frankfurt responded to the attacks by stepping up the number of police on patrol at their airports and other transport hubs. Airlines scrambled to divert flights as Brussels airport announced it would remain closed on Wednesday.
“Two terrorists who enter the terminal area with explosive devices, this is undoubtedly a colossal failure,” Pini Schiff, the former security chief at Tel Aviv’s Ben-Gurion Airport and currently the CEO of the Israel Security Association, said in an interview with Israel Radio.
In the United States, the country’s largest cities were placed on high alert and the National Guard was called in to increase security at New York City’s two airports.
A United Nations agency was already reviewing airport security following the downing of a Russian airliner in Egypt by a makeshift soda-can bomb in October last year. Islamic State has claimed responsibility for smuggling the bomb on board.
But despite attacks like a suicide bomb at Moscow’s Domodedovo airport’s arrival hall in 2011 that killed 37 people, there has been less attention focused on how airports themselves are secured.
“It strikes me as strange that only half of the airport is secure. Surely the whole airport should be secure, from the minute you arrive in the car park,” said Matthew Finn, managing director of independent aviation security consultants Augmentiq.
The relative openness of public airport areas in Western Europe contrasts with some in Africa, the Middle East and Southeast Asia, where travellers’ documents and belongings are checked before they are allowed to enter the airport building.
In Turkey, passengers and bags are screened on entering the terminal and again after check-in. Moscow also checks people at terminal entrances.
Israel’s Ben Gurion Airport is known for its tough security, including passenger profiling to identify those viewed as suspicious, bomb sniffing devices and questioning of each individual traveller.
In the Kenyan capital Nairobi, where authorities are on high alert for attacks by Somali-based al Shabaab militants, passengers have to get out of their cars, which are then searched, at a checkpoint a kilometre from the main terminal.
But adding checks such as bag X-rays at terminal entrances could themselves create a potential target, one analyst said.
“Any movement of the security ‘comb’ to the public entrance of a terminal building would cause congestion, inconvenience and flight delays, while the inevitable resulting queues would themselves present an attractive target,” said Ben Vogel, Editor, IHS Jane’s Airport Review.
Large numbers of uniformed police officers and National Guard troops dressed in battle fatigues and carrying rifles patrolled New York’s John F Kennedy International Airport. Several US carriers - Delta Air Lines Inc, United Continental Holdings Inc and American Airlines Group Inc - said they cancelled or rerouted flights as a result of the Brussels attacks.
At mid afternoon, authorities at the Denver airport evacuated two levels on the west side of the main terminal after several packages that appeared suspicious were spotted near ticket counters, airport spokeswoman Stacey Stegman said.
Denver police, FBI and US Transportation Security Administration officers converged on the airport, but the packages were ultimately deemed to pose no threat, and the terminal was fully reopened within two hours.
Several airlines were affected by the scare, including American Airlines, Aeroméxico, Air Canada, Lufthansa and British Airways, the airport said.
‘World must unite’
US President Barack Obama ordered flags flown at half-staff in memory of the victims in the Belgium attacks.
The State Department said an undetermined number of US citizens had been injured in Brussels but none were killed. Three Mormon missionaries and a US Air Force member and his family were among those hurt.
The Obama administration also was expected to impose tighter security measures at US airports following the Brussels Airport bombings, which occurred in a public hall outside of the security check area.
US representative William Keating of Massachusetts, senior Democrat on a House subcommittee on terrorism, said the suicide bombings illustrated the difficulty of protecting “soft targets” outside tightly controlled security cordons.
“The targets aren’t going to be just getting on the plane itself, but the airport in general,” he said in a phone interview.
Obama addressed the attacks briefly in a speech in Havana on his historic visit to Cuba, vowing to support Belgium as it hunts for those responsible.
“This is yet another reminder that the world must unite. We must be together regardless of nationality or race or faith in fighting against the scourge of terrorism,” Obama said.