Chinese President Xi Jinping has warned against “impermissible” challenges to Beijing’s authority over Hong Kong.
Mr Xi was speaking at the swearing-in of the territory’s new leader Carrie Lam, as it marks 20 years since its handover to China from Britain.
He took part in a series of lavish events, including a flag-raising ceremony, amid tight police security.
But clashes took place between pro-democracy and pro-Beijing demonstrators close to the site. Several were held.
The visit was Mr Xi’s first to the city since becoming leader in 2013 and comes three years after mass pro-democracy rallies crippled parts of the territory for months.