There have been chaotic scenes at Hong Kong's legislative assembly as lawmakers for and against controversial amendments to the territory's extradition law clashed over access to the chamber.

At least one person was taken from the chamber on a gurney following Saturday morning's melee, in which legislators grappled with each other on the floor and amid seats and tables.

The amendments have been widely criticized as eroding the semi-autonomous Chinese territory's legal independence by making it easier to send criminal suspects to mainland China, where they could face vague national security charges and unfair trials.

Under the "one country, two systems" framework, Hong Kong was guaranteed the right to retain its own social, legal and political systems for 50 years following its handover from British to Chinese rule in 1997.