Too many indoor house parties have led to trends creeping in the wrong direction, Governor Murphy said during a news conference.
"The actions of a few knuckleheads leave us no choice," he said.
The rate of transmission, which indicates the number of people an infected person spreads the virus to, has climbed from 0.87 a month ago to 1.48 on Monday.
"We cannot be any clearer than indoor gatherings, especially large crowded ones where social distancing isn't practiced and face masks aren't worn. They just are not safe. But as I warned and we weren't on Friday, we would not hesitate to take direction to further clamp down on indoor gatherings," he said.
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In addition to the indoor gathering restrictions, the governor also said that face coverings will be required at all times for all students in the coming school year. That's a change from before, when the state Education Department was strongly recommending face coverings for students.
"We know that face coverings work, and we will now ensure that everyone in the school building will wear one," Murphy said.
New Jersey is in the second of three reopening phases, but Murphy warned last week that virus trends are heading in the wrong direction and setting off alarm bells.
With information from the Associated Press
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