BEIJING - Beijing is getting tough with those who violate traffic restrictions and production suspension after the first-ever red alert for smog was issued on Monday.

As of 6 p.m. on Tuesday, the traffic police had found 3,690 breaches of car use restrictions.

More than 1,000 cases involving cement trucks and other prohibited vehicles were found on Tuesday.

"After the red alert was issued, our workload nearly tripled," said Wu Peng, deputy head of the tail gas discharge administration station in Daxing District.

The municipal environment protection bureau inspected 587 major pollutant dischargers on Tuesday and found 38 of them did not abide by the order of production suspension.

At the Xinshipai Stone Processing Company in Daxing District, workers were still processing stone in a dusty, smelly workshop.

"Stone processing obviously affects the air quality and should be suspended under a red alert," said a law enforcement officer on condition of anonymity.

Schools have been closed, work at outdoor construction sites suspended, and factories have been ordered to halt operations till Thursday noon. Beijing also closed several highway sections to reduce traffic.