Updated at 6:22 p.m. ET: LONDON -- An 11-year-old boy flew alone from England to Rome after boarding a commercial flight without a passport, boarding pass or cash, officials said Wednesday.

Several members of staff at Manchester International Airport and with discount air carrier Jet2.com have been suspended and an inquiry has been launched in the wake of the incident during the height of the summer travel season, officials told NBC News.

The boy is now back home with his family and the airport is treating it as "a very serious incident," an airport spokesperson told NBC News by telephone.

Punning on the popular "Home Alone" movies starring Macaulay Culkin in the 1990s, British newspapers are calling it the "Rome alone" incident.

The case of the stowaway boy comes as international travelers pour into Britain just two days before the opening ceremonies of the Summer Olympics in London, less than 200 miles to the southeast.

"I treat security breaches very, very seriously indeed, so we are now reviewing urgently with Manchester Airport, and indeed the airline, exactly what happened," British Transport Secretary Justine Greening told the BBC.

Five security checks
The boy, who was named in local media reports as Liam Corcoran, managed to pass through five security checks by tagging along with another family before boarding the plane, according to reports.

The plane's captain was notified that his flight had an extra passenger after the aircraft was already in flight, the Manchester Evening News reported. Airplane staff kept the boy onboard after landing at Rome’s Fiumicino Airport and he stayed on the plane until it returned to Manchester later Tuesday.

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"This extremely serious matter is now being urgently investigated by officials from the airport and airline. It is clear that documentation has not been checked correctly at security and the boarding gate. The boy went through full security screening so the safety of passengers and the aircraft was never compromised. We made preparations to ensure that his return to the U.K. was handled sensitively to avoid any distress," the airport said in a statement sent to NBC News.

The flight from Manchester to Rome is approximately 1,500 miles.

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The boy did not pose a security risk because he passed through all of the proper security procedures, the airport spokesperson and the airline told NBC.

"We have launched a full investigation into what is a serious incident, and the staff involved have been suspended pending the outcome. The boy has been returned safely to his family," a spokesperson from Jet2.com said in a statement given to NBC News.

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'He seemed ... quite unfazed'
The boy had disappeared just after noon Tuesday during a trip with his mother to a shopping center in Wythenshawe, on the south side of Manchester, before making his way to the airport, a Manchester police spokesperson told NBC News. Local reports said the boy wanted to run away from home.

"He was very talkative and seemed quite unfazed by it all. He was just sat there chatting away about how he'd been trying to run away from home," airplane passenger Sarah Swayne, 26, from Nantwich, England, told the Evening News.

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"He seemed quite innocent really and I don't think it had sunk in how serious the situation was," she told the newspaper.

"When the plane touched down, he clearly didn't want to get off but he was taken down the steps before everyone else and met at the bottom by a group of staff who quickly whisked him away," another passenger, who did not provide a name, told the Evening News.

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