Workers put up a board outside Metropark Hotel Causeway Bay Hong Kong believed to be used as the temporary national security agency in the city in Hong Kong, China July 7, 2020.

Workers place a national emblem outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

Security reacts as journalist get close to Metropark Hotel Causeway Bay Hong Kong believed to be used as the temporary national security agency in the city in Hong Kong, China July 7, 2020.

Workers place a national emblem outside the Metropark Hotel Causeway Bay, Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

A man is seen inside Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

A worker walks past a board after the opening of a temporary national security office, in Hong Kong, China July 8, 2020.

Former Chief Executive Tung Chee-hwa (C) attends the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Workers work on a board after the opening of temporary national security office, in Hong Kong, China July 8, 2020.

The Chinese national flag flies on a flagstaff after the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Police officers stand guard outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

Journalists film behind water filled barriers after the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Workers put up a board outside Metropark Hotel Causeway Bay Hong Kong believed to be used as the temporary national security agency in the city in Hong Kong, China July 7, 2020.

A police officer walks past water filled barriers after the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Water filled barriers are seen surrounding the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, as workers place a national emblem at midnight, in Hong Kong, China July 8, 2020.

People's Liberation Army officers attend the opening ceremony of temporary national security office, in Hong Kong, China July 8, 2020.

Workers move water filled barriers outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

People walk past water filled barriers after the opening ceremony of temporary national security office, in Hong Kong, China July 8, 2020.

Director of the Liaison Office of China Luo Huining speaks during an opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Police officers stand guard outside Metropark Hotel Causeway Bay Hong Kong believed to be used as the temporary national security agency in the city in Hong Kong, China July 7, 2020.

Police officers stand guard outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

Workers put up a board outside Metropark Hotel Causeway Bay Hong Kong believed to be used as the temporary national security agency in the city in Hong Kong, China July 7, 2020.

Workers place a national emblem outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.

A journalist takes video through water filled barriers after the opening ceremony of temporary national security office, in Hong Kong, China July 8, 2020.

Journalists film behind water filled barriers after the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

A journalist takes video through water filled barriers after the opening ceremony of a temporary national security office, in Hong Kong, China July 8, 2020.

Workers place a national emblem outside the Metropark Hotel Causeway Bay Hong Kong, believed to be used by the temporary national security office, at midnight, in Hong Kong, China July 8, 2020.