Latest round of smog expected to stay until Sunday, ministry says

China has seen its air quality worsen a little in the first quarter, particularly in the Beijing-Tianjin-Hebei region, the national environmental authority said on Monday.

"In the first three months, 71 percent of days in 338 cities tracked had good air quality, 0.9 percent higher than the same period last year, but the concentration of PM2.5 increased 3.3 percent year-on-year," said Liu Zhiquan, head of the environmental monitoring department at the Ministry of Environmental Protection.