What not to wear boarding a flight... a pair of electronic massage shoes (complete with batteries and an on/off switch) Read more:

Daily mail - A passenger was detained by airport authorities in Pakistan after electrical circuits and batteries were found in the soles of his tennis shoes, an airport security official said today. Officials were investigating what the components could be used for and why they were concealed. 

Similar materials can be used in the construction of bombs.

Faiz Mohammad was arrested at Karachi's Jinnah International Airport last night, said Munir Ahmed, a spokesman for the airport security force.

The materials were detected by a scanner.

Mr Ahmed said each shoe contained a small circuit connected to two AAA batteries.

Mohammad, a building constructor who was heading for Muscat in Oman, told investigators he bought the shoes from a market in Karachi and had no idea there were circuits hidden inside the soles.

'It is premature to say what was he up to. We are looking into the matter thoroughly,' police official Sohail Faiz said.

In 2001, British extremist Richard Reid was arrested after he tried to detonate explosives hidden in his shoes on a transatlantic flight.

Pakistan's security efforts have come under scrutiny since an alleged Pakistani-trained extremist was accused of a failed car bombing in Times Square last week. 

Top US officials have said the Pakistani Taliban were behind the plot.

Karachi, Pakistan's largest city, was targeted by authorities in the investigation into the Times Square bombing attempt. Four people with alleged links to Jaish-e-Mohammed, a militant group affiliated with al Qaeda, were detained there.

Read more: http://www.dailymail.co.uk/news/worldnews/article-1275952/Pakistani-air-passenger-caught-electronic-circuits-concealed-shoes.html#ixzz0ncWfboxm