Shoes trigger airport security alert

Officials are on alert since Reid allegedly tried to use "shoe bombs"

A man wearing electrically warmed shoes has caused a major alert at San Francisco airport.

Security officials spotted a pair of black slip-on shoes in the man's carry-on luggage shortly before he was due to board a connecting flight to New York and on to Shanghai.

The shoes were found to contain batteries, wires and a heating device designed to keep his feet warm.

The passenger, a Chinese man, was detained. But since he did not speak English, he could not explain why the shoes had wires hanging from them or how to disconnect the batteries.

Bomb squad officials then blew up the shoes in a remote corner of the airport.

The man was later allowed to board a later flight to New York.

Shoe scares

"This gentleman... had a battery in his shoe and when it went through the X-ray machine that caught everyone's attention," airport spokesman Mike McCarron said.

"It turns out it was some kind of heated shoe of some type - I don't know what that means - but they've run the passenger's name through records and it comes up clean right now," Mr McCarron added.

Airport screeners have been paying close attention to passengers' shoes following an alleged attempt by a British man, Richard Reid, to blow up a US airliner late last year using shoes lined with explosives.

In January, officials evacuated a large part of San Francisco airport after guards detected possible explosive residue on the shoes of a passenger - but he disappeared into the crowd before he could be questioned.

Officials later said the residue could well have been traces of simple lawn fertilizer.