Covid-19 is spreading out of control in Hong Kong with a record 100 new cases confirmed, chief executive Carrie Lam said on Sunday, July 19.

The financial hub has returned to tightening social distancing measures to tackle the sudden surge in infections.

This setback was despite the city's impressive success in tackling the virus that saw local transmissions cut to zero by late June.

However, since the first week of July, infections have spiked once more.

Doctors now fear a new outbreak is spreading undetected among 7.5 million people.

Lam said more than 500 infections had been confirmed in the last two weeks, accounting for nearly a third since the outbreak began.

"I think the situation is really critical and there is no sign the situation is being brought under control," Lam told reporters.

A total of 108 new infections were recorded by health authorities on Sunday alone, a daily high.

The total number of cases hit 1,886.

New measures

Hong Kong instituted new social distancing measures in mid-July.

Many businesses including bars, gyms and nightclubs were shuttered, and everyone was ordered to wear masks on public transport.

Restaurants can only offer takeout services in the evenings.

Lam announced more measures on Sunday, including plans to make it compulsory to wear masks inside any public indoor venue.

Non-essential civil servants will have to work from home -- a new order for the city.

Officials are rushing to build a further 2,000 isolation rooms on barren land near the city's Disneyland resort for those who test positive.

More economic woes

The current partial lockdown has added to the city's economic misery, after it was already plunged into recession due to unrest and the U.S.-China trade war.

Lam also called for landlords to offer lower rents in the notoriously expensive city where inequality is rampant.

She said further social distancing measures would be rolled out if the daily infection rate continues to be high in coming days.

However, she said she was keen to avoid ordering people to remain at home.

"We can't just make a simple and extreme move to cut everything at once," Lam said.

She also said officials would try to strike a balance between protecting health and keeping the economy partially afloat.

"It's hard to tell what kind of measures we will need to roll out... many places have ordered people to stay home," she said.

"We haven't adopted that in the last six months because we wanted to maintain a normal life for everyone."