Chinese President Xi Jinping sworn in the new leader of Hong Kong, Carrie Lam, on Saturday as the region marked 20 years of its handover to China from Britain. She is Hong Kong’s first female leader, reported BBC.

Civil servant Lam was selected as the next leader in March by a 1,200-plus election committee that mostly included pro-China and pro-establishment loyalists, according to Reuters. However, the Chinese president warned against “impermissible” challenges to Beijing’s authority. He added that Hong Kong now enjoyed more freedom than ever before.

The swearing-in ceremony was marked by lavish events, including a flag-raising ceremony. Among those who attended the event were outgoing Chief Executive Leung Chun-ying and former Chief Executive Tung Chee-hwa, reported South China Morning Post. The ceremony was held amid tight security.

Meanwhile, scuffles broke out as pro-democracy activists clashed with pro-Beijing groups. Hundreds of police personnel were deployed across Hong Kong. Pro-democracy party Demosisto told BBC that the police arrested five of its members and four from the League of Social Democrats. Other reports claimed that more than 20 activists were taken away by the police.

Britain had handed over Hong Kong to China on July 1, 1997, under a “one country, two systems” formula. The system guarantees autonomy and judicial independence to Hong Kong.