BEIJING (REUTERS) - China's environment minister has conceded that his ministry ranks among the world's "four major embarrassing departments", but defended the agency, saying it is hampered by overlapping functions in government.

The comments by Mr Zhou Shengxian are the latest in a string of blunt admissions by Chinese leaders that the country still has a long way to go in tackling pollution. Public anger over smog that blanketed many northern cities in January has spread to online appeals for Beijing to clean up water supplies, especially after the rotting corpses of thousands of pigs were found in March in a river that supplies Shanghai's water. Social unrest spurred by environmental complaints is becoming common across the country, to the government's alarm.

"I've heard that there are four major embarrassing departments in the world, and that China's ministry of environmental protection is one of them," state news agency Xinhua's official microblog account quoted Mr Zhou as saying.

"Our environmental work involves many departments. Many of the functions are overlapping," he said, adding that water, land and carbon output were all managed by different ministries.

Despite Xinhua later removing a reference to Mr Zhou's remarks describing the agency as an embarrassment, his comments spread widely on China's other state media microblogs.

Mr Zhou, a two-term environment minister, has presided over China's worst pollution in recent memory. He received among the fewest votes from China's lawmakers in the race for the Cabinet at this year's meeting of the National People's Congress, a largely rubberstamp Parliament body.

Mr Zhou said he was worried about the public health impact of dire pollution contaminating the air, soil and water, Xinhua said.

"The current challenge facing the environmental (authorities) is how to properly deal with the environmental problems caused by economic development," he said.