Chiang Mai - A crude bomb exploded at the government-backed civil organization office in the outskirts of Burma's former capital city Rangoon early on Tuesday, an eyewitness said.

The bomb went off at about 6 am in the morning, in the office of the Union Solidarity and Development Association (USDA), which is located behind the local Township Peace and Development Council office in Rangoon's suburb township of Shwepyithar, the eyewitness said.

"The bomb suddenly exploded in the USDA office this morning," the eyewitness said. "But there were no casualties," he added.

After the blast, the police cordoned off about 50 metres from the scene of occurrence and security was tightened, the eyewitness said. "Security was beefed up and roads near the scene were sealed," he told Mizzima. No group has claimed responsibility for the blast yet.

The Burmese military government, which has always been quick in blaming dissidents and ethnic armed rebels, who are fighting for autonomy, for such incidents, has so far not blamed any group.

The blast on Tuesday is the first since April, when two bombs exploded in downtown Rangoon, causing damages to cars but no casualties.

The government had blamed an armed student group in exile, Vigorous Burma Student Warriors, who oppose military rule, for the blasts in April.

USDA, a pro-military junta civil organization, was formed by junta chief Snr. Gen Than Shwe almost 15 years ago. The organization, which played a vital role in crushing the monks' protests in September last year, claims it has a membership of more than 24 million.

Members of USDA and Swan Arrshin, another pro-junta civil organization, were reportedly behind the deadly attacks on Burma's pro-democracy leader Daw Aung San Suu Kyi's motorcade during her political tour in Depeyin town in May 2003.