Transit site bombs found identical in structure, composition

The explosives found at Seoul’s two major transit hubs have been found identical in structure and composition, the Seoul Metropolitan Police Agency said Friday.

The National Forensic Service discovered that the same bags, butane canisters and digital battery timers were used in the explosives that went off at Seoul Station and Seoul Express Bus Terminal.

Police said the 20-liter mountain climbing backpacks were of the same brand. The digital timer and 12-volt batteries were connected to the explosives in electric wires together with chrome-coated exothermic materials.

After a period of time, the timer turned on the battery to provide electric currents to the exothermic materials to produce heat. Police say they believe that the heat caused the powder contained in glass bottles to go on fire.

The powder detected in the burned materials was composed of potassium chlorate, sulfur, magnesium and aluminum that can be easily obtained on the streets and used in firecrackers.

The butane canisters did not explode at both sites despite the perpetrator’s intent. Police say the culprit will likely be an ordinary person discontent with society or has a strong wish to show off.

A Seoul police official said mock tests will determine why the explosives did not go off as planned.

Police are tracing a suspect by examining surveillance TV footage and traffic card usage while questioning sellers of the bags and batteries.

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