Hong Kong will roll out compulsory testing for Covid-19 starting in mid-March for its 7.4 million residents, leader Carrie Lam said on Tuesday, as university researchers predicted new infections could peak at a staggering 180,000 a day next month.

Stringent coronavirus rules would be in place until mid-April with schools breaking early for summer and resuming the new year in August, she said, as authorities battle an "exponential" rise in infections that have overwhelmed the healthcare system.

Hong Kong is home to some of the most densely populated districts on Earth, with the majority of people living in high-rise apartment blocks cheek by jowl with family members and often sharing cramped lifts.

"The coming one to three months are crucial in...