China met its targets for improving water quality in rivers and lakes last year despite figures showing conditions worsened in some regions, the Ministry of Environmental Protection said on Monday.

Of the 1,940 stations monitoring surface water quality nationwide, just over two-thirds - 67.8 percent - reported quality within the top three levels of the nation's six-tier system in 2016, Zhang Bo, the ministry's director of water quality management, said at a news conference.

This represents an increase of 1.8 percentage points year-on-year, according to the ministry.

Meanwhile, the proportion of surface water reported to be at the lowest quality level was 8.6 percent last year, Zhang said, a decrease of 1.1 percentage points compared with the ministry's data for 2015.

Both figures were slightly better than the targets set early last year.

The surface water quality system has six pollution levels. Surface water that meets a standard for the first three levels can be used for drinking water.

"We met the targets set on the surface water quality in 2016. However, there is still a long way until we meet the public's expectation for clean water," Zhang said ahead of World Water Day on Wednesday.

While the surface water quality has generally improved, in some areas the water quality has grown worse, he said.

Last year, 25 monitoring stations recorded that quality dropped from the top three levels into the bottom three, while 22 stations recorded quality dropping to the worst level, the ministry's data show.

The ministry also named "and shamed" two cities - Yangquan of Shanxi province in North China and Weinan of Shaanxi province in the Northwest - "due to their poor performance in water pollution controls", Zhang said.

In Yangquan, ministry inspectors found more than 40,000 metric tons of sewage was discharged into rivers directly every day between January and September, according to an earlier statement from the ministry.

In Weinan, untreated sewage from industrial zones was discharged into a river directly and caused it to turn red. The pollution problem was noted in August but not solved until November.

Data from the ministry also show 84.6 percent of underground drinking water sources met the national standard last year, a decrease from 86.6 percent in 2015.

"Various sources like fertilizer used in agriculture, industrial production and even surface water pollution could make underground water polluted, which may take a long time to recover," said Guo Lei, from an environmental group on water pollution in Guangzhou, Guangdong province.

zhengjinran@chinadaily.com.cn