Yemeni Woman Detained in Terror Plot

The first rounded up so far. We expect many more.

Yemeni authorities on Saturday arrested a woman thought to be involved in sending explosive packages headed to the United States and were searching for more suspects belived linked to al-Qaida, Yemeni security officials said.

The arrest came after authorities surrounded a house where she was hiding in the capital San'a, Reuters reported.

A security official told Reuters that authorities traced the woman through a telephone number she left with a cargo company.

Always snared through their own stupidity.

More on the plot here.

Sophisticated bombs contained in packages sent from Yemen were designed to explode in the air and bring down the cargo planes carrying them, the government confirmed.

Intelligence experts believe the use of the devices, contained in printer cartridges on board two Chicago-bound cargo planes, represents a shift in terrorist tactics to commercial targets.

Both devices, one discovered in the hold of a plane that landed at East Midlands airport after flying from Cologne, the other on a plane in Dubai, were described as "extremely professional" by intelligence officials.

One of the devices was linked to a mobile phone, while the other was attached to a timer. The Observer understands that the East Midlands device was so sophisticated an examination by forensics experts initially suggested it did not contain explosives.

"Even when it was examined, the sniffer dogs couldn't detect it," a security source said. "It was only when they [forensics experts] had a second look at it they realised what it was."

It has emerged the devices were discovered only after a tip-off from Saudi intelligence. "This… started with good information from the Saudis," the US homeland security secretary, Janet Napolitano, confirmed. "We were then immediately able to work with other countries, particularly the UK and the UAE, to segregate these packages, to begin the analysis about what they were, what they could have done."

If the devices had blown up over the Atlantic, or any other large stretch of water, identifying the cause would have been difficult because there would have been little trace left of the planes.