Most Hollywood productions have shut down again until at least mid-January, the film industry's acting union announced, as Covid-19 cases soar to record levels in Los Angeles.
Sag-Aftra said the majority of entertainment productions will "remain on hiatus until the second or third week of January if not later", in a statement to members on Tuesday.
A list of productions affected by the latest restrictions has not yet been released.
The message comes after Los Angeles county health officials on Christmas Eve urged filmmakers to "consider pausing work for a few weeks during this catastrophic surge in Covid-19 cases".
Los Angeles – the nation's most populous county – has emerged as the latest US epicentre of the coronavirus pandemic, topping 7,000 Covid-19-related hospitalisations for the first time on Monday.
The sprawling county of 10 million people has suffered more than 750,000 cases including just more than 10,000 deaths.
Southern California's "stay-at-home" order was extended indefinitely on Tuesday, with several hospitals overwhelmed and forced to turn away ambulances.
Sag-Aftra has steered months-long efforts to restart Hollywood since its initial March shutdown, co-signing a deal with top studios in September to ramp up on-set coronavirus safety measures for its actors, including testing.
Even so, Los Angeles entertainment productions were at less than half their usual activity levels in October, before again declining as Covid-19 cases began to soar.
Film LA, the body that grants permits for productions around Los Angeles, said applications to film have recently sunk to "lows we have not seen since the weeks after restart of production last summer".
Beside a few dozen indie films, very few features resumed production in the Los Angeles area this year, with most filming activity restricted to commercials and music video shoots.
In contrast, high-profile productions have resumed abroad, including the latest Tom Cruise blockbuster Mission Impossible 7 in the UK and Italy, and TV series such as Supergirl and Batwoman in Canada.
Lack of coronavirus insurance continues to hamper productions hoping to restart.
Sag-Aftra said it would ensure "appropriate precautions for the holiday hiatus period including additional time for testing prior to the resumption of production".