EXCLUSIVE: Photos of the Northwest Airlines Flight 253 Bomb

Accused Bomber Abdulmutallab's Underwear, Explosive Packet and Detonator

A singed pair of underwear with a packet of powder sewn into the crotch, seen in government photos obtained exclusively by ABC News, is all that remains of al Qaeda's attempt to down an American passenger plane over Detroit.

As seen in these photos, the alleged bomb consisted of a packet of powder sewn into the briefs of Umar Farouk Abdulmutallab, a 23-year-old Nigerian. Al Qaeda took credit Monday for the attempted bombing, boasted of its ability to overcome U.S. intelligence and airport security, and promised new attacks.

The first photo, to the left, shows the slightly charred underpants with the bomb packet still in place. All photos include a ruler to provide scale.

The bomb packet is a six-inch long container of the high-explosive chemical PETN, less than a half cup in volume, weighing about 80 grams.

In the second photo (right), the packet of explosive powder has been removed from the underpants and displayed separately.

A government test with 50 grams of PETN blew a hole in the side of an airliner. That was the amount in the bomb carried by the so-called shoe bomber Richard Reid over Christmas 2001.

The underpants bomb would have been one and a half times as powerful.