Brisbane, Australia's third-largest city, to enter three-day Covid-19 lockdown

About 2 million people in the city, the country's third largest and the capital of Queensland state, will be required to stay home from 5 pm local time except for essential work, healthcare, grocery shopping or exercise.

Australian authorities announced a snap three-day Covid-19 lockdown in the northern city of Brisbane from Monday afternoon, as they attempt to stamp out an outbreak of the virulent UK variant of the virus.

A couple sit on a dock to look at the sails of the Sydney Opera House that are illuminated with the green and gold colors of the Australian Olympic team. (AP)

About 2 million people in the city, the country's third largest and the capital of Queensland state, will be required to stay home from 5 p.m. local time except for essential work, healthcare, grocery shopping or exercise.

"I know this is a really big call and I know it is really tough," Queensland state Premier Annastacia Palaszczuk told reporters. "We have Easter coming up, we have school holidays coming up but let's do it now and let's do it right."

State officials reported four new locally transmitted COVID-19 cases on Monday, taking the cluster of cases linked to the UK variant to seven. The first case in the new cluster was reported on Friday.

Palaszczuk pointed to the success of a snap three-day lockdown in Brisbane in early January after the discovery of a single case of the UK variant.

"That worked very well when we did that last time," she said.

Snap lockdowns, social distancing rules and speedy contact tracing systems have helped Australia to contain fresh clusters in recent months. It has reported just over 29,200 cases and 909 deaths since the pandemic began.

The Brisbane lockdown is currently scheduled to finish just before the Easter long weekend and school term break in Australia, usually a popular time for people to travel.

Schools in the city will be closed from Tuesday, funerals capped at 20 people and weddings limited to 10 people. The number of international travellers - largely returning citizens and permanent residents - allowed into Brisbane has been halved.

Virgin Australia said all its domestic flights into the city were operating as normal on Monday but schedules could be changed in response to demand.