San Francisco police have shot and killed a man who crashed his car into the Chinese consulate on Monday.
A police statement said the unidentified man was shot after officers arrived at the scene.
Footage online showed a blue Honda car in the lobby and dozens of people fleeing the consulate building.
A consulate statement condemned the incident, adding that it posed a “serious threat” to the safety of its staff and other people at the scene.
China’s foreign ministry has accused the unidentified individual of breaking into the consulate to hurt people inside the office.
The consulate has since temporarily closed parts of its office and has lodged solemn representations – a phrase for expressing diplomatic discontent – to the US, urging authorities to ensure that the matter is properly dealt with.
Police said that an open and active investigation was under way but have not revealed much information.
She said that the police were coordinating with officials from the US state department for the investigation, adding: “There’s very little information that we can give at this time.”
Police say they are still trying to ascertain exactly how many people were in the office at the time of the incident.
Pictures from the consulate soon after the car was driven into the building, show a heavy police presence with the consulate building in the city’s Japantown area cordoned off.
Queue barriers and chairs lay toppled in the lobby, while other pieces of furniture were damaged.
No injuries have been reported from inside the consulate.
San Francisco will host the Asia-Pacific Economic Cooperation next month with Chinese President Xi Jinping expected to attend.