California has reimposed restrictions on businesses and public spaces amid a spike of coronavirus infections in America's most populous state.

Governor Gavin Newsom on Monday ordered an immediate halt to all indoor activities at restaurants, bars, entertainment venues, zoos and museums.

In the worst-affected counties of the south-western US state, churches, gyms and hairdressers will also close.

California has more than 330,000 Covid-19 cases, with more than 7,000 deaths.

The reimposition of the restrictions in the state with nearly 40 million people was prompted by a 20% rise in people testing positive in the past two weeks and increasing numbers of Californians are now needing intensive care.

Infections have risen rapidly in about 40 of America's 50 states over the last two weeks, according to an analysis by Reuters news agency.

Along with California, Florida, Arizona and Texas have emerged as centres of the pandemic. Towns and counties across Florida have been reinstating restrictions that were lifted in May when infections began to drop.

But on the east coast, New York City - which in April had one of the highest Covid-19 death rates in the world - recorded no new fatalities from the disease for the first time in four months.

There are currently more than 3.3 million confirmed Covid-19 cases across the country, and more than 135,000 deaths, according to Johns Hopkins University.

Governor Newsom warned on Monday that "this virus is not going away anytime soon".

"I hope all of us recognise that if we were still connected to some notion that somehow when it gets warm it's going to go away or somehow it's going to take summer months or weekends off - this virus has done neither.

"We are now effective today requiring all counties to close their indoor activities, their indoor operations in the following sectors: restaurants, wineries, tasting rooms, movie theatres, family entertainment centres, zoos and museums, card rooms and the shuttering of all bars.

"This is in every county in the state of California."

The new measures reverse the easing of the state's strict lockdown in May and then again in June, when restaurants, bars and gyms reopened with in counties that met the state's safety guidelines.

Dr Robert Wachter, chair of the Department of Medicine at University of California San Francisco, told the BBC World Service some people seemed to have got complacent in the fight against the disease.

"It was appropriate to begin easing the restrictions," he said.

"We were doing so well and things seemed under control. And so the restrictions were eased but I think people took that as the starting gun for changing behaviour too much. So yes people were allowed to go out and around but they were supposed to wearing a mask. They were supposed to be keeping their distance. They were supposed to be avoiding large crowds. And I think too many people got a little bit complacent.

"And as you know in the United States the messaging on things like masks has been quite muddied in part because the federal government has been very unclear and sometimes unhelpful."

Tensions have grown between President Donald Trump and the country's infectious disease chief, Dr Anthony Fauci, over the handling of the pandemic.

Dr Fauci has contradicted Mr Trump's comments on the pandemic a number of times, pushing back on his claims that the outbreak is improving and attributing hasty state reopenings to the recent surges. (BBC)

Update news