LONDON (AFP, REUTERS) - Britain's support for Hong Kong and "its freedoms is unwavering", Foreign Secretary Jeremy Hunt said on Monday (July 1), but warned anti-government protesters against violence after they stormed the city's parliament.

The prime ministerial candidate tweeted "to stress UK support for Hong Kong and its freedoms is UNWAVERING on this anniversary day.

"No violence is acceptable but HK people MUST preserve right to peaceful protest exercised within the law, as hundreds of thousands of brave people showed today," he added.

The protesters seized the parliament's main debating chamber late Monday, daubing its walls with graffiti and fixing a British colonial-era flag to the main podium, an AFP reporter on the scene said.

Hunt last week called for an independent investigation into clashes between police and protesters, and suspended export licences for crowd control equipment.

The European Union, meanwhile, called for restraint and dialogue to find a way forward.

"In the wake of these latest incidents, it is all the more important to exercise restraint, avoiding escalatory responses, and to engage in dialogue and consultation to find a way forward," a spokeswoman for EU foreign policy chief Federica Mogherini said in a statement.

"The actions today of a small number of people, who attempted to force their way into the Legislative Council premises, are not representative of the vast majority of demonstrators, who have been peaceful throughout successive protests."

Hong Kong has been rocked by the worst political unrest since its 1997 handover from Britain to China.