DUBAI, United Arab Emirates—One of two mail bombs addressed to a synagogue in Chicago was transported on a passenger airplane, it emerged on Sunday.
The bomb, which was hidden in printer cartridges and sent via airmail from Yemen, was carried on a passenger jet to the Doha International Airport in Qatar, before being transferred to a cargo plane headed for Dubai, according to a statement by Qatar Airways.
The second letter bomb was discovered in East Midlands Airport in the U.K. after being transferred from Cologne, Germany.
British authorities believe that the device was designed to go off midair.
The bombs, which were carried by UPS and FedEx, contained the explosive PETN—that is difficult to detect with traditional airport screening. The explosives were only discovered after Saudi security forces tipped off officials in Dubai and the U.K.
In a statement on the company’s website, state-owned airline Qatar Airways shifted blame away from airport security in Doha for failing to detect the device before it was sent to Dubai.
“It is not the responsibility of the country in which the cargo transits to x-ray or inspect the cargo,” the statement said. “This responsibility belongs to the country from where the consignment originates.”
“Furthermore, the explosives discovered were of a sophisticated nature whereby they could not be detected by x-ray screening or trained sniffer dogs. The explosives were only discovered after an intelligence tip off.”
U.K. Home Secretary Theresa May said Sunday that the country has banned unaccompanied freight from Yemen.
In a bid to improve its image, Sana’a moved quickly to arrest a suspect in the plot, who was named Sunday as 22-year-old female university student Hanan al-Samawi.
The arrest sparked protests at the campus of the University of Sana’a. Yemen President Ali Abdullah Saleh said that the information leading to the arrest had come from the UAE and U.S. intelligence communities.
Samawi was released Sunday after Yemeni officials said her name and ID had been used by another woman, according to Reuters.
Barack Obama's counterterrorism adviser John Brennan has singled out Ibrahim Hassan al-Asiri as the mastermind of the attack. Al-Asiri, is believed to be the figure behind the attempt to blow up an airliner over Detroit on Christmas day last year.
"I think that the indications are right now based on forensic analysis that the individual responsible for putting these devices together is the same," he told ABC news.
He added, that governments should “presume” there might be more similar attacks in future.