PHOTO: ANDY WONG/AP PHOTO.

Officials in Beijing have declared a red alert, China’s highest alarm level, in reaction to the city’s air pollution. The announcement marks the first air-pollution red alert since Beijing created the color-based warning system in 2013.

Under the red alert, schools in Beijing will be closed between 7 a.m. local time on Tuesday until noon on Thursday. Cars will be able to drive only on alternating days, and fireworks and outdoor grilling will be banned, The New York Times reports.

To qualify for a red alert, the air-quality index must be predicted to be above 200 for more than 72 hours, the Times explains. By U.S. standards, a level-200 air quality is “very unhealthy,” and 301 to 500 is “hazardous.” On Monday evening, when the red alert was announced, Beijing’s air-quality level was gauged at 253.

An August study from a climate-research group projects that China’s air pollution causes about 4,400 deaths every day. More than a third of China’s population breathes “unhealthy” air regularly, according to researchers. Air pollution can contribute to asthma, heart disease, strokes, and lung cancer, according to the Times.

Earlier this month, an orange alert for air pollution in Beijing reportedly prompted officials to close local schools. During the orange alert, the smog was at its most hazardous levels in 13 months, the BBC reported. To symbolize the side effects of breathing in dangerous air — Beijing residents have been wearing face masks to protect themselves — a performance artistcreated a brick made from dust particles gathered from the city’s smog.