On 20 January 2007, some 15 military officers and civilians were arrested in commando raids regarding the bombings.
When the second purported plot was reported last month, 27 military men and civilians were arrested; four people's whereabouts are unknown.
Four other civilians were arrested in the raid, he said.
Several thousand civilians and activists were arrested after the disputed presidential election in 2009.
Over 800 civilians were arrested in the following days, and over 200 of them were sentenced by courts.
In all 646 soldiers and civilians were arrested and accused of supporting the rebellion.
Earlier, in the last week of March, 28 officers and civilians had been arrested for reportedly planning a coup against the government.
Eight soldiers, one officer, and four civilians were arrested and charged with murder.
Two civilians and two army officers have been arrested for the massacre, though witnesses said 200 people carried out the attack.
Almost 80 civilians were arrested, tried and given very heavy prison sentences, ranging from six to 28 years.