Chinese Defense Ministry spokesman Wu Qian said at a news conference Wednesday morning that the protests on Sunday were "intolerable."

"Some radical protesters' actions challenge the authority of the central government and the bottom line of 'One Country, Two Systems,'" Wu said, adding that the ministry would follow Article 14 of Hong Kong's Basic Law.

"One Country, Two Systems" is China's way of referring to its administration of Hong Kong, under which it is part of China but allowed to maintain some degree of autonomy. Article 14 states that the Chinese government's military forces stationed in Hong Kong will not interfere in local affairs unless the Hong Kong government requests assistance "in the maintenance of public order" or for disaster relief.

As mass protests against a proposed extradition bill morphed into a desperate pro-democracy movement in Hong Kong over the last two months, the local government has denied rumors that the Chinese military might intervene. Some analysts who study Hong Kong expressed skepticism that Beijing would send its military, which could have devastating consequences.