Amid the bombed-out ruins of Mosul University, U.S. officials say they have uncovered evidence that the Islamic State of Iraq and Syria (ISIS) was developing a new type of bomb that could pass through an airport scanner undetected.

CBS News joined Iraqi Special Forces in Mosul just days after the hard-fought battle to recapture the University in January. It’s long been believed that Mosul University was the center of the militants’ bomb-making projects, using the school’s equipment and labs.

Now, U.S. officials believe that research includes a new generation of more powerful explosives that could be concealed in a computer.

When ISIS overran Mosul in 2014, they also captured the city’s international airport. And with it, all the modern security scanner and screening equipment necessary to test their new bombs.

On CBS News’ trip, there were certain no-go areas. Iraqi forces kept us well away from entering the most sensitive buildings, warning that ISIS had booby-trapped them.

A commander told us ISIS had also torched some of the facilities in order to hide evidence. But it appears what was left behind has given U.S. officials new cause for concern.

The threat from ISIS has already led, in part, to the U.S. banning electronics on flights from ten airports in the Middle East and Africa. Talks are now underway on whether to expand that ban to cities in Europe.

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