Yangon: An explosion on a bus in Myanmar's largest city killed seven passengers 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 travelled from Yangon to a northern suburb, an official said.

The blast, which also injured one person, occurred at 2:40am

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