"Due to security reasons, the Central Government Offices (CGO) will be temporarily closed today and tomorrow (June 13 and 14)," the statement read.
The government of the Chinese special administrative region specified that CGO staff should not come to the offices but "work in accordance with the contingency plans of their respective bureaus or departments."
"All visits to the CGO will be postponed or canceled," the Hong Kong government added.
Tens of thousands of people protested in Hong Kong on Wednesday the proposed amendments that they see as an attack on Hong Kong's autonomy. This is the second biggest rally since the weekend, when over 1 million people took to the streets.
Changes to the extradition law, if adopted, would allow the Hong Kong government extradite suspects to various jurisdictions, including mainland China, without any bilateral agreement.