YANGON (Myanmar) - AN EXPLOSION on a bus in Myanmar's largest city killed seven passengers on Monday, officials said, adding that a preliminary investigation did not point to terrorism.

Initial findings showed a natural gas tank inside bus exploded as the vehicle traveled from Yangon to a northern suburb, an official said on condition of anonymity because he was not authorized to speak to reporters.

The blast, which also injured one person, occurred at 4.10am.

Terrorism is relatively rare in military-ruled Myanmar. On Sept 9, an explosion on a passenger bus in Yangon injured three people, and several small-scale bombings have occurred in recent years.

The government often blames the attacks on opponents of the regime or ethnic rebel groups seeking autonomy.

The military has ruled Myanmar, formerly called Burma, since 1962 and has been widely criticised for suppressing basic freedoms. -- AP