Burma's government says rebels trained abroad by a "superpower" were behind last week's bombings at three shopping centres in the capital, Rangoon.
The government says the terrorists and explosive came from abroad
Nineteen people are known to have died in the blasts, with 69 injured.
The explosives used were not available in the country, and the plot was funded by a "world famous organisation", the military government said.
The junta said it believes the attacks were led by the Thailand-based All Burma Students Democratic Front.
"It is crystal clear that the terrorists... and the time bombs originated from training conducted with foreign experts at a place in a neighbouring country by a world famous organisation of a certain superpower nation," Information Minister Kyaw Hsan told reporters.
He also accused the unnamed organisation - based in Washington - of having given $100,000 (£54,000) to a dissident group led by a cousin of pro-democracy leader Aung San Suu Kyi.
The group then sent a group of saboteurs to Burma to carry out the attacks, helped by ethnic Shan, Karen and Karenni rebels, the minister added.
The three minority ethnic groups have denied any involvement.
Even though the minister refused to name the suspected country and organisation, correspondents believe he was referring to the United States and the CIA.
The bombs went off at two supermarkets and at a conference centre in Rangoon on 7 May.
The Thai-based National Coalition Government of the Union of Burma, which has led a government in exile since 1990, has alleged the government might have had the bombs planted to blame the opposition.