TAIPEI (AFP) - A Taiwan court on Wednesday jailed two men for a bizarre plot in which they planted suitcases containing petrol and cyanide on a train and in a politician's office hoping to profit from the investor panic they thought would ensue.

The mastermind of the high-profile case, identified only by his family name Hu, was sentenced to 22 years on charges of attempted murder, the New Taipei City District Court said in a statement.

Hu, 45, a lawyer who was familiar with stock and futures trading, had planned to stir investor panic with the scare and make a profit from the events, it said.

His accomplice, 47-year-old Chu who was found to have helped Hu in planting the bombs, was jailed for 12 years, it said.

"As a lawyer, instead of walking on the right path, Hu used his knowledge to produce highly risky explosive and poisonous gas devices and plant them on a high-speed train and in a busy street, which could endanger the lives of many people," it said.

No one was injured in either case and their hoped-for stockmarket panic failed to materialise.

In the first incident, two unattended suitcases were found on board a train bound for Taipei in April last year, prompting the evacuation of more than 600 passengers.

Several hours later, two other suitcases were found outside lawmaker Lu Chia-chen's office in New Taipei city.

The four suitcases all contained petrol, gas canisters, clocks, and wires.

Sodium cyanide and hydrochloric acid, which can produce poisonous hydrogen cyanide if mixed, were also found in the bags, according to police.

The pair fled to Macau on the same flight after the incidents and were nabbed in the southern Chinese city of Zhuhai two days later. They were later extradited back to Taiwan.

The high-speed rail bomb scare - the first of its kind since the system using Japanese bullet-train technology went into operation in 2007 - had rocked Taiwan, prompting calls for beefing up railway security.