Newsom's announcement came after officials in Orange and Ventura Counties allowed access to their beaches even as state parks remained closed, prompting families and groups to head to the ocean on a warm spring weekend.

The crowds put at risk the state's progress in slowing the advance of the novel coronavirus and could delay a loosening of restrictions that was just weeks away, said Newsom, a Democrat.

The beach crowds exemplify the tension that officials throughout the United States are dealing with as residents chafe under stay-at-home orders and some states begin to loosen them.

Newsom said he would not direct state police or park rangers to issue citations to individuals who were just out quietly with their children or walking their dogs.

"I don’t want to be punitive," he said. "They just want to take a rest on the beach and all of a sudden they get a citation - I don’t want to see that. But if there are people thumbing their nose and taking a risk ... I think we may have to do a little bit more."

The two counties that opened their beaches are reconsidering their plans after people thronged their shoreline spots, prompting criticism from public health authorities, Newsom said.

He warned that the coronavirus outbreak was not over in California, where 45 people have of COVID-19 in the past 24 hours and 1,300 more cases were diagnosed.

"The virus is as transmissible as it’s ever been," Newsom said. "It doesn’t take the weekend off. It doesn’t take any time off. It is ubiquitous, it is invisible and it remains deadly."

Late on Monday, seven Bay Area public health officials issued a statement saying the counties of Alameda, Contra Costa, Marin, San Francisco, San Mateo, and Santa Clara as well as the city of Berkeley would issue revised "shelter-in-place" orders this week.

The current orders will expire on May 3.

The new orders will keep the restrictions in place and extend them through May, they said, while adding there would be limited easing for a small number of low-risk activities.

Two additional states, Nevada and Colorado, have joined California, Oregon and Washington to develop a Western regional plan for reopening their economies and allowing residents to begin more typical social interactions.

But coordinating public health rules and schedules for re-opening across five states may be complicated.

Hours after Newsom chastised Californians for crowding the beaches, Washington Governor Jay Inslee said his state's parks and other outdoor areas would reopen on May 5 for golf, hunting, fishing and other recreational activities.

Members of the public will be expected to follow public health guidelines, and the parks would close again if illnesses spike, Inslee said, but the announcement stood in contrast to the California governor's efforts to keep beaches closed.

"Outdoor recreation is one of the best things we can do to promote physical, mental and emotional well-being for Washingtonians during a time of great stress and isolation," Inslee said.