"If the CNS is so good as to know the culprits behind the bombing, then why not arrest them all?" he asked, challenging authorities to issue an arrest warrant against him.

"Saprang Kalayanamitr (CNS assistant secretary) claimed he already had pertinent information on the bombing, but he failed to take any action. This is gross incompetence," he said.

He said the CNS should examine among its ranks if it truly wanted to solve the case, alluding to speculation that the military had staged the bombing in order to justify its grab for power.

Younger military officers were inexperienced, although they tried to act as if they knew everything, he said. Even foreigners knew that the bomb attacks were an insider's job as rival Thais sought to destroy one another, he said.

In explaining why he was suspected, he said he was often blamed for things he did not do. "In the past, I was accused of being a communist sympathiser while combating insurgency," he said.

"In a recent case, (deposed premier) Thaksin Shinawatra removed me from solving the outbreak of southern violence because he suspected I was a Muslim sympathiser," he added.

He warned that the violence might escalate if the CNS held on to power. The only way to restore normalcy is for the CNS to quickly hand back the power to the people, he said.

In a separate interview, Lt-General Pirat Sawamipak, seen as Chavalit's ally, denied his involvement in the bomb attacks.

Pirat admitted, however, that authorities had checked on his whereabouts after the explosions. "I told them I was at home as I am too old for partying," he said.

He said he also informed his alibi to General Pongthep Thesprateep, secretary-general to the prime minister.

He dismissed speculation that his house had been searched and that he and Chavalit might be detained for questioning.