US investigators see link between packages, `underwear` bomb

US investigators believe that the same persons who built the crude Christmas Day `underwear bomb` were behind the PETN-based devices hidden in packages sent from Yemen, designed to bring down an airplane.

Washington: US investigators believe that
the same person or persons who built the crude Christmas Day
`underwear bomb` were behind the PETN-based devices hidden in
packages sent from Yemen, designed to bring down an airplane.

"The thinking is it`s the same person or group of people
that built the underwear bomb because of the way it`s put
together," CNN quoted a US government official as saying.

The unnamed official, who had been briefed by multiple
US authorities and law enforcement sources, said the explosive
device found this time was about four times as powerful.

One package was found in Dubai in the United Arab
Emirates. The other was discovered at an airport in England.

On Friday, US officials said they had not taken a
position on whether planes or two Chicago, Illinois,
synagogues were the ultimate targets. The packages had the
synagogue addresses.

Meanwhile, a woman believed to be connected to the plot
to send explosive packages bound for the United States has
been arrested in the Yemeni capital of Sanaa.

A female relative of the woman was also being questioned
by Yemeni authorities, the government official said. The
relationship between the two women was not immediately known.

Authorities are looking at a specific material found in
the devices and used in the foiled "underwear bomb" attempt on
Christmas Day in 2009.

A source close to the investigation said the type of
material found in the devices was PETN, a highly explosive
organic compound belonging to the same chemical family as
nitroglycerin. Six grams of PETN are enough to blow a hole in
the fuselage of an aircraft.

PETN was allegedly one of the components of the bomb
concealed by Umar Farouk AbdulMutallab, the Nigerian man
accused of trying to set off a bomb hidden in his underwear
aboard a Northwest Airlines flight as it approached Detroit,
Michigan, on December 25 last year.

AbdulMutallab is alleged to have been carrying 80 grams
of PETN in that botched attack.

"The quantity of PETN in these (new) devices was about
five times the volume used at Christmas" by AbdulMutallab,
Col Richard Kemp, the former chairman of the British
government`s Cobra Intelligence Group, said.

The plot "does appear to be a typical al Qaeda-type
operation," he said.

A source closely involved in the investigation said the
detonating substance was Lead Azide, a "very powerful
initiator" which is easily prepared and is a standard
substance in detonations. Believing that a Yemen affiliate of al Qaeda was
involved, American and British authorities said explosive
devices jammed into ink toner cartridges were powerful enough
to bring down a large aircraft.

British authorities said they believe East Midlands
Airport in central England was simply a conduit for shipment
of one device to the United States.

As they studied the devices and toiled to understand the
extent of the plot, authorities pointed their fingers at al-
Qaeda in the Arabian Peninsula. The group is based in Yemen, a
poor Arab nation that has emerged as a major operating base
for al Qaeda and other terror groups.

Authorities, meanwhile, said the explosive devices were
meticulously crafted.

They were "professionally" loaded and connected using an
electric circuit to a mobile phone chip tucked in a printer,
Dubai police said. The devices were packed in toner cartridges
and designed to be detonated by a cell phone.

The package found at East Midlands Airport contained a
"manipulated" toner cartridge and had white powder on it as
well as wires and a circuit board. A similar package set to be
shipped on a FedEx cargo plane was discovered in Dubai,
officials there said.

When the Saudis warned British law enforcement that there
were explosives inside the cartridge at East Midlands, the
British -- using human and canines -- could not detect the
material, according to a US law enforcement official familiar
with investigation.

The British authorities contacted the Saudis to verify
the tip, the official said. The Saudis told them to inspect
the cartridge again, and that is when the British authorities
discovered the material, the official said.

In response to the threat, authorities stepped up
searches on Friday of cargo planes and trucks in several US
cities, said law enforcement sources with detailed knowledge
of the investigation.

Also on Friday, the Transportation Security
Administration stopped all packages originating from Yemen.

Britain has said that all cargo into or through the
United Kingdom originating in Yemen have been halted. The US
Postal Service also announced a temporary suspension of
acceptance of inbound international mail originating in Yemen.