New York

US coronavirus deaths passed a quarter of a million people Wednesday as New York announced it would close schools to battle a rise in infections and anti-restriction protests in Europe turned violent.

America has now registered 250,426 fatalities, according to a running tally by Johns Hopkins University, by far the highest reported national death toll.

US states and cities were imposing a raft of new restrictions, including home confinement, the closure of indoor dining and a limit on gatherings as cases soar across the country, with more than 157,950 new infections recorded over the past 24 hours on Wednesday.

New York Mayor Bill de Blasio said the city's 1,800 public schools would revert to remote learning beginning Thursday after the Big Apple recorded a seven-day average positivity rate of three percent.

"We must fight back the second wave of Covid-19," he said.

Most-populous city

The toughened measures in America's most-populous city came despite pharma giant Pfizer boosting hopes of a possible end to the pandemic by announcing improved results for its vaccine.

Europe meanwhile remains the hardest-hit region, accounting for 46 per cent of new global cases and 49 percent of deaths last week, according to the World Health Organisation (WHO).

Its figures additionally showed the only region where cases and deaths declined last week was Southeast Asia.

Worldwide, more than 1.3 million people have died of Covid-19 and over 55 million have been reported infected with the virus since it first surfaced in China late last year, according to a tally from official sources compiled by AFP.

In Switzerland, one of the worst-hit countries in Europe, the Swiss Society for Intensive Care Medicine (SSMI) warned that intensive care units "are practically all full."

More beds have been added, and the Swiss military has been called in to support efforts in several areas.

Water cannon fired in Berlin

Many European countries are extending heavy restrictions on daily life in attempts to curb the spread of the virus.

A French government spokesman said authorities are unlikely to lift a partial lockdown any time soon while Portugal's government was preparing to extend measures for two more weeks.

In Hungary, a state of emergency that enables partial lockdown measures has now been extended until February.

In Berlin, police fired water cannon to disperse thousands of unmasked protesters demonstrating against tightened restrictions.

The protesters, who have equated the restrictions to Nazi-era rules, responded by chanting "Shame! Shame!"

The protest came a day after clashes with police at a similar demonstration in the Slovak capital Bratislava attended by thousands of far-right supporters.

EU summit

Despite the impact of the virus, efforts to tackle the pandemic were expected be side-lined at Thursday's EU summit due to a row stemming from Hungary and Poland's opposition to Brussels' oversight over the rule of law.

In Russia, President Vladimir Putin voiced alarm at his country's rising fatality rate but stopped short of introducing strict measures seen in many European countries.

Meanwhile, Iranian President Hassan Rouhani said he would impose "severe restrictions" in many areas of his country from Saturday.

And in Central America coronavirus efforts are being threatened by the hurricane season, according to the Pan American Health Organization, which said it anticipates an increase in infections in the wake of Iota and Eta which wreaked havoc on the region over the past weeks.

In the right direction

There was more encouraging news out of Belgium, which has had one of the highest death rates in Europe since the start of the pandemic, where authorities said a month-long semi-lockdown was beginning to work.

"For the first time in weeks, or even for several months, all indicators are going in the right direction, meaning they are all going down: The number of infections, hospitalizations and — for the first time — the number of deaths," said Covid-19 Crisis Centre spokesman Yves Van Laethem.

While less affected, other parts of the world have continued to feel the impact of the virus.

South Australia announced a six-day "circuit-breaker" lockdown for its population of nearly two million people Wednesday to contain an outbreak that ended a monthslong streak of no infections.

Schools, shops, pubs, factories and even takeaway restaurants were told to close and stay-at-home orders were issued for residents.

Japan was on "maximum alert" after logging a record number of daily coronavirus infections, leaving authorities to consider restrictions like limiting groups allowed in restaurants.

Pfizer offered some relief by saying a completed study of its experimental vaccine showed it was 95 percent effective.

The announcement came after another US firm involved in the vaccine race, Moderna, said this week that its own candidate was 94.5 percent effective.