Hong Kong's new Legislative Council members have taken the territory's official oath of office.
Leung Kwok-hung added pro-democracy slogans to his oath
In last month's elections, 25 of the 60 seats went to pro-democracy candidates - more than ever before.
The new members are likely to create problems for Hong Kong's leader Tung Chee-hwa and his pro-China government.
One of the newly-elected legislators, Leung Kwok-hung, has already caused controversy by adding a number of pro-democracy slogans to his official oath.
"Long live the people! Power to the people!" he shouted, punching the air.
He had initially refused to swear the oath at all, despite the fact that the pledge, which promises loyalty to the Chinese and Hong Kong governments and the territory's constitution, is compulsory.
Mr Leung - a radical activist known as Longhair - said he would rather promise support for human rights, justice, freedom and democracy.
But earlier on Wednesday, a judge threw out his case, warning he could face expulsion if he refused to comply.
So far no action has been taken against him.
Platform for dissent
The LegCo's role is simply to scrutinise government policy and legislation, and pass its budget.
But it also provides a useful platform for those who want to express dissent.
Mr Tung and his allies in Beijing were no doubt relieved that the pro-democracy camp fell short of its aspirations at last month's elections and only won 25 seats.
But nevertheless, a significant number of democrats were elected - and some of them are among the government's fiercest critics.
These include Longhair, renowned for his Che Guevara T-shirts and Marxist views, and a controversial radio host who resigned from his show saying he had been threatened for his anti-government views.
If nothing else, the election of some colourful characters should ensure that Hong Kong politics in the months to come are far from dull, according to our correspondent in the territory, Chris Hogg.
Hong Kong's electorate is becoming increasingly restless for change, and Mr Tung is the usual target for blame.
Lawmakers from different sides of the chamber have recently criticised his policy of cutting welfare payments for elderly and disabled people.
Electoral reform, too, remains a contentious issue.
Although direct elections have been ruled out to choose a successor for Mr Tung in three years' time, the government is considering what limited reforms to the electoral system might be brought in.
Meanwhile China and Hong Kong have reacted angrily to US criticism over the way the territory is run.
The report, by the US Congressional Executive Commission on China, said the authorities in both Beijing and Hong Kong had tried to delay democratic reforms and intimidate pro-democracy advocates.
But China's foreign ministry said the report did not reflect the truth, and urged the US commission to stop interfering in China's internal affairs.
Hong Kong's government has also published a point-by-point rebuttal of the US claims.
It insisted that basic freedoms of the press, of expression, assembly and religion, remained strong in Hong Kong.
A senior government official, Constitutional Affairs Secretary Stephen Lam, echoing the comments from Beijing, appealed to foreign governments to respect the principle that Hong Kong affairs are best dealt with by the territory's government.