YANGON -- The US embassy in Yangon, the largest city of Myanmar, conducted a safety drill on Sunday night, during which a fire alarm has been triggered, according to local sources.

The embassy used a tear gas grenade during the drill, which triggered the embassy's fire alarm system and alarm systems in the surrounding area, at over 8 pm local time (1330 GMT).

It has been earlier believed that an explosion has taken place, the sources said.

The embassy apologized for not informing the police in advance. A press conference will be held on Monday morning.