SHAH ALAM (June 4, 2009) : The mystery as to how thieves could single out vehicles for the laptops stored inside has been resolved with the arrest of two Indonesian men.

Khalid takes a look at gadget used by the thieves.

Police found that the suspects had used an inductive amplifier -- an electronic device similar to a handheld metal detector and as small as a hairbush -- to "sniff" out laptops kept in parked cars.

Selangor police chief DCP Datuk Khalid Abu Bakar said today the men, aged 20 and 39, were arrested in an ambush at Kampung Changkat, Gombak at about 7.30pm on Tuesday.

He said police recovered the gadget and seized several laptops, custom-made break-in tools, handbags and watches among other items.

The suspects are believed to be behind at least 20 cases of theft of items stored in cars.

Khalid said the younger suspect did not possess any travel documents while the other man had an expired passport.

He said police learnt that the men had purchased the gadget from an electronic shop. The conventional use of the inductive amplifier is the location of breaks in hidden wires, even buried in concrete. The typical wire detection range in a concrete wall is 10-20 cm.

He said police are also investigating if the suspects are involved in the forging of fake travel documents and work permits as a few such items and a colour printer were seized from them.

He said police are looking for several other members of the gang.

Meanwhile, the operation to weed out underworld gangs in the state continued yesterday when Kuala Selangor and state police arrested about 20 people at the Tennamaram Estate, Batang Berjuntai for suspected gangland activities.

Khalid said those arrested are suspected to be from the notorious 08 Gang and 21 Gang and are being probed for a string of crimes such as rioting, murder, extortion, causing grevious hurt, robbery and arson.

"We urge the public to provide us with information about these gangs. Do not be afraid of these gangs." he added.