Thailand's powerful military council on Wednesday declared that New Year's Eve bomb attacks in Bangkok were staged by politicians and renegade army officers loyal to exiled Prime Minister Thaksin Shinawatra who want to topple the government.

It vowed to severely punish those behind the bombings, which killed three people and wounded nearly 40 while the city was in the midst of New Year's celebrations.

"The evidence and intelligence information proves that the bombs were the dirty work of politicians who lost power and benefit. Some bad soldiers loyal to the bad politicians collaborated with them with the intention to topple this government," said Gen. Saprang Kanlayanamitr, a member of the Council for National Security.

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The council was set up after generals toppled Thaksin in a bloodless coup Sept. 19. It later appointed an interim civilian government to run the country until promised elections in October.

Thaksin, in a handwritten letter faxed Tuesday from China and distributed by his lawyer in Thailand, accused the interim government of Prime Minister Surayud Chulanont of unfairly implying he was behind the violence.

"I strongly condemn this act (of bombing) and I swear that I never ever think of hurting the people and destroying the country's credibility for my own political gain," Thaksin said in the letter, given to reporters.

He also said he suspected Islamic separatists, who have waged a bloody insurgency in the country's southernmost provinces for the past three years, may have been responsible for the eight small blasts that shattered Sunday night's celebrations.

"The bandits and terrorist groups in southern Thailand had no links or connections to the bombs in Bangkok," Saprang told reporters.

No arrests have yet been made but Saprang said that the days of compromise with the former power-brokers were over and "from now on there will be no compromise."

Saprang hinted that former Prime Minister Gen. Chavalit Yongchaiyudh was part of the pro-Thaksin camp, saying the group had "used an old soldier to launch a war of words against the government and (council)." Chavalit has sharply criticized the interim government recently.

The bombings, which included nine foreigners among the wounded, have raised concerns about Thailand's stability, shaky economy and thriving tourism industry.

Deputy Prime Minister Pridiyathorn Devakula said the New Year's Eve bomb attack will not harm the economy in the long run.

"The bomb attacks will not affect the GDP (Gross Domestic Product) in the long run but it is affecting the tourist sector in the short term," Pridiyathorn told reporters.

The attacks capped a year of unrest in Thailand, including the coup and the increasingly violent Muslim insurgency in the south, which has claimed almost 2,000 lives since 2004.

Nobody has claimed responsibility for the blasts, though the military-backed government has virtually ruled out southern insurgents, instead focusing on supporters of Thaksin as suspects.

Thaksin said the bombings could be related to the southern violence because they were similar to explosions that killed four people and wounded dozens last September in Hat Yai, the south's commercial hub near the three Muslim-dominated southern provinces rocked by the insurgency.

"The insurgents have a strong notion to separate from Thailand or at least gain autonomy," he wrote. "I used to warn high-ranking officials that if we can't stop them ... they will go to Bangkok."

Several analysts noted the military itself was a possible suspect in the bombings, perhaps aiming to demonize the former prime minister and excuse the continuation of martial law, imposed during the September takeover and still in effect in some parts of the country.

Bangkok has rarely experienced deadly bombings, although several small explosions took place during recent political turmoil in an apparent attempt to create a sense of instability, rather than cause casualties.

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