Weeks of unrest in the Chinese territory have begun to overwhelm Hong Kong’s police, who have found themselves in violent clashes with protesters. China warned Monday that the civil disorder had gone “far beyond” peaceful protest after police deployed tear gas over the weekend.

The nature of the Chinese buildup wasn’t clear; the official said that units of the Chinese military or armed police had gathered at the border with Hong Kong. The official briefed reporters on a range of issues on condition he not be identified.

Eurasia Group China analyst Andrew Coflan said he was taking the White House concerns “with a grain of salt” as it was unclear whether the White House was merely observing a large swearing-in ceremony of around 19,000 police personnel in China’s southern Guangdong province.