Video clips posted online showed smoke in the air outside the diplomatic compound in the Chinese capital and police roping off a perimeter around the area, with witnesses saying an explosion had occurred.
The location appeared to be near where Chinese citizens typically line up to enter the US embassy for visa interviews.
However, the details of the incident were not immediately clear as witness reports conflicted.
The US Embassy declined comment and Chinese security forces could not immediately be reached.
The diplomatic area where the incident took place is on the outskirts of Beijing and home to several embassies, including those of the United States, India and Israel.//AFP