BEIJING, July 27 -- Air pollution is still public enemy number one in China's war against pollution, according to the country's environmental watchdog.

Among the 696 complaints received by the Ministry of Environmental Protection in the first half of this year, 558 of the total, or 80 percent, were related to air quality, an 8.4-percent year-on-year increase, according to a ministry statement.

All the complaints were lodged through the telephone hotline "12369." Other major reasons for complaints were water and noise pollution.

The ministry said 474 of the complaints have been investigated, with problems confirmed in 382 cases, or 80.6 percent.

Companies found responsible for the problems received punishments ranging from warnings to suspension, closure and fines.

"Some enterprises became involved in disputes because of a lack of planning in how industrial parks and residential quarters are located," said the statement.

In one case, it said, the Foxconn Industrial Park in Taiyuan City in Shanxi Province is located just across the street from a residential quarter. Though monitoring results show that the factory is discharging legally, residents still are affected by strange odors.

In other cases, big projects have caused outrage in neighborhoods by starting operations without passing an environmental impact assessment or paying fair compensation.