Bad smog ahead: Beijing tells students to stay indoors

Beijing: Authorities in Beijing are warning that heavy pollution will persist in the city this week and say outdoor activities in schools should be stopped and construction projects will be suspended.

The warning comes in the form of an orange alert, the second highest in a four-tier warning system. The alert signifies there will be three consecutive days of smog at particularly dangerous levels on the Chinese capital's air quality index. Schools were advised to cancel outdoor activities.

The warning system is one way authorities are attempting to clean up China's dirty air after decades of breakneck economic growth.

Authorities say they're making progress. Environmental officials in Beijing said Monday that a key indicator of poor air quality decreased in the first 10 months year-on-year.