• President Xi Jinping arrives in Hong Kong under heightened security on his first visit as China’s leader as the city celebrates the 20th anniversary of its return from Britain.

Mr. Xi’s attendance at the swearing-in of Beijing’s preferred choice for chief executive, Carrie Lam, is among several ceremonies meant to convey a message of China’s firm control.

“They’re trying to make Hong Kong people get used to the demonstration of central authority,” one Hong Kong scholar said.