SEOUL, Aug. 26 (Yonhap) -- A Seoul man was sentenced to five years in prison on Friday for exploding homemade bombs at crowded public transportation stations in May in a plot he designed to cause a plunge in the stock market.

The Seoul Central District Court handed down the jail term to the 43-year-old man surnamed Kim who was accused of setting off two explosives at the main bus terminal in southern Seoul and Seoul Station in May.

Kim plotted the bombing attacks to cause big losses in the stock market in a bid to make money off his holdings of stock derivatives, which were structured to yield profits upon a drop in local shares, according to court records.

Aided by information Kim gathered from Internet postings, he assembled cans of butane gas, gunpowder found in fireworks and timers into explosives and hired two men to place the homemade bombs in public lockers at the stations. The two accomplices were acquitted of their criminal charges.

No casualties were reported in the explosions, which caused only minor fires.

Kim hatched the plan after suffering massive losses in the stock market and racking up more than 300 million won (US$277,315) in debt due to his investment.

The court said he deserved the severe punishment given "severe risks of the explosives installed at crowded places and his attempts to cover up the plan."