BRATISLAVA, Slovakia — A failed airport security test ended up with a Slovak man unwittingly carrying hidden explosives in his luggage on a flight to Dublin, Slovak officials admitted today — a mistake that enraged Irish authorities and shocked aviation experts worldwide.

While the Slovaks blamed the incident on “a silly and unprofessional mistake,” Irish officials and security experts said it was foolish for the Slovaks to hide actual bomb parts in the luggage of innocent passengers under any circumstances.

The passenger himself was detained by Irish police for several hours before being let go without charge Tuesday.

The Irish were also angry that it took the Slovaks three days to tell them about the Saturday mistake and that the pilot of the airplane decided to fly to Dublin anyway even after being told that an explosive was in his aircraft’s checked luggage.

After being informed by the Slovaks, Irish authorities shut down a major Dublin intersection Tuesday and evacuated people from several apartment buildings as Irish Army experts examined the explosive.

The unwitting passenger was identified by Irish police as Stefan Gonda, a 49-year-old Slovak electrician who lives and works in Ireland.

The incident was bound to heighten flying jitters in the wake of the Christmas near-disaster where, authorities say, a 23-year-old Nigerian suspect tried to detonate an explosive device aboard a Northwest Airlines flight from Amsterdam to Detroit, only to be foiled by a passenger who jumped over seats to subdue him.

Security experts said the Dublin episode illustrated the inadequacy of the screening of checked-in luggage — the very point Slovak authorities had sought to test when they placed bomb components in passengers’ bags.

Yet Clark Kent Ervin, the former inspector general of the U.S. Homeland Security Department, called the Slovak test “crazy.”

“It should be a controlled exercise,” Ervin said. “It never should be done to someone unwittingly.”

“It’s unbelievable, it’s astonishing,” said Rick Nelson, a former Bush administration official who worked at the National Counterterrorism Center. “I’m not sure what they were thinking using an unknowing civilian rather than an undercover security official.”

Their comments were echoed by experts in several nations.

Aviation analyst Chris Yates said someone should be fired, not only for the mistake, but for how the entire operation was designed.

“The whole idea of putting devices in passenger bags scares the living daylights out of me, frankly. It leaves it wide open to a whole range of things, including theft,” Yates told The Associated Press in London.

“Anything could happen,” he said. “That bag could go through a different carousel in the airport, you could lose it and you get the situation where you have RDX plastic explosive loaded into the cargo hold of an airplane, flown to another destination and then you have to find (it).”

Aviation security experts in Israel, considered among the top in the world, were equally incredulous.

Rafi Sela, president of AR Challenges, a consulting firm specializing in security, said Israel conducts daily drills in which people try to smuggle mock explosives, but the explosives are monitored at all times and are handled by volunteers, never by unwitting travelers.

“Nothing has ever happened like that in Israel and it never will because we operate differently here,” he told the AP. “It’s extremely dangerous what happened there. We send people to try and get through security all the time to test the system but explosives are always closely monitored and would never end up unattended like that.”

In Hungary, officials said placing explosives secretly in a passenger’s luggage was against the law.

Slovak Interior Minister Robert Kalinak expressed “profound regret” to the Irish government for the oversight and the delay in alerting them.

But his ministry, in a statement, still claimed that “no one was in danger (during the flight) because the substance, without any other components (detonators) and under the conditions it was stored, is not dangerous.”

The ministry said it ordered an immediate halt to such tests and took steps to prevent a repeat, while Tibor Mako, the head of Slovakia’s border and foreign police whose people carried out the exercise, offered his resignation. There was no word on whether it would be accepted.

“The aim of the training was to keep sniffer dogs in shape and on alert in a real environment,” the ministry said.

Still, details emerging from the failed exercise heightened concerns that basic precautions were not taken, with the ministry saying that when Slovak authorities realized their error and told the pilot of the Danube Wings flight, he still decided to take off with the explosives on board.

The Slovaks say authorities at Poprad-Tatry Airport informed their Dublin airport counterparts during the flight that the explosive was onboard. The Dublin Airport Authority and airport police, however, said the information was sent to a private baggage company, not to them.

Even the basic facts of test were in dispute today.

Irish officials said the Slovaks told them nine real bomb components were placed into the bags of nine different passengers at two airports, including Bratislava Airport and Poprad-Tatry Airport in central Slovakia. Eight items were detected, the Irish said, adding that one bag had two bomb components in it.

Slovak officials say they attached only two small packages onto the outside of one man’s bag — one a small explosive cache and the other a dummy that smells like explosives.

The sniffer dog found one explosive but the police officer in charge failed to remove the second, which was not detected by the dog, from the bag because he was busy, the Slovakian interior ministry statement said.

That allowed 3 ounces of RDX plastic explosive to travel undetected through security at Poprad-Tatry Airport onto a Danube Wings aircraft. The Slovak carrier launched services to Dublin last month.

“The police officer made a silly and unprofessional mistake, which turned the good purpose of protecting people into a problem,” the ministry statement said.

Slovak border police subsequently traced the man and told him where the explosive was planted so that he was able to find it Monday evening, said the ministry. Kalinak, the interior minister, called him to apologize.

But the Slovak ministry admitted it did not contact Irish authorities and explain the situation until Tuesday. That prompted Irish police to raid the man’s Dublin apartment and detain him for several hours.

Irish police said they initially were led to believe the man might be a terrorist until the Slovaks explained the situation further.

Irish Justice Minister Dermot Ahern said Dublin police eventually confirmed that the explosive “was concealed without his knowledge or consent … as part of an airport security exercise.”

The Slovak statement criticized the Irish police.

“For an incomprehensible reason for us, they took the person into custody and undertook further security measures,” it said.

Slovakia was considering “new forms of sniffer dog training” to avoid a repeat of the scare, the ministry said.

In the Slovak capital of Bratislava, people expressed mixed feelings about the mistake.

“It’s a big deal, I think it’s horrible,” said Robert Maslej, 28, waiting for his flight to Manchester, England at Bratislava airport.

But Neil Hamison, a 30-year-old IT engineer booked on the same plane, was far less perturbed.

“I saw it on the news but didn’t really think about it,” he said.

The incident was reminiscent of a French security exercise gone awry six years ago, when a bag of plastic explosives hidden intentionally in an unwitting passenger’s luggage went missing.

Police had placed explosives in the side pocket of a suitcase in an exercise to train bomb-sniffing dogs at Paris’ Charles de Gaulle airport. The bag, containing nearly 5 ounces of explosives, was never seen again.

French police said at the time there was no chance the explosives could go off since they were not connected to detonators, but the incident caused widespread criticism. The French subsequently stopped placing explosives intentionally into passengers’ luggage for training.