Maj. Gen. Tan Benhong, the commander of the People's Liberation Army in Hong Kong, was a picture of uniformed calm as he shared champagne toasts with Chinese officials on Wednesday at local celebrations marking China's national day.

The streets surrounding the bash at the Hong Kong Convention and Exhibition Centre presented a starkly different scene as thousands of protesters escalated the most sustained push for full democracy since China took Hong Kong back from Britain in 1997.

As the protests enter their second week amid fresh signs of street violence, some demonstrators and ordinary Hong Kong citizens fear Tan's troops could eventually be ordered to crush a movement unthinkable on the mainland.