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 involved cement trucks and other prohibited vehicles.
Meanwhile, the municipal environment protection bureau inspected nearly 600 major pollutant dischargers on Tuesday and found 38 of them did not abide by the order of production suspension.
After Beijing issued the red alert, the most serious level, for smog, 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.