"The administration has set up two regional environment watchdogs in Guangzhou and Shanghai and will launch another three in Chengdu, Xi'an and Shenyang over the next four months to ensure local governments abide by environment protection laws, as well as meet standards in regional economic development," said Zhang Lijun, a deputy director of SEPA, in Guangzhou, capital of Guangdong Province.

"This is an important step to remove local protectionism, a major obstacle in our law enforcement."

Zhang Jianming, head of the south China watchdog, said the administration has mediated a number of inter-provincial pollution disputes since it was launched three years ago. The watchdog was also credited with helping local authorities solve several severe pollution incidents including the cadmium spill along the Beijiang River in December 2005. The spill threatened drinking and agricultural water supplies in Guangdong.

Cadmium, a metallic element widely used in batteries, can cause liver and kidney damage and lead to bone diseases. Compounds containing cadmium are also carcinogenic.

China suffered a string of environmental disasters last year, including a lead poisoning accident caused by a factory in Gansu Province that hospitalized about 250 children and left hundreds of others with excessive amounts of lead in their blood.

Last September, two factories in Yueyang, Hunan Province, flushed waste water with a high concentration of arsenide into the Xinqiang River. The incident affected the water supply for 80,000 residents along the lower reaches of the river.

"Governments are almost always behind these seemingly corporate behaviors - local authorities sometimes tolerate environmental violations as they want to boost economic growth," said Pan Yue, another SEPA deputy director.

He said the refusal and failure of governments to fulfill environmental responsibilities and interference in law enforcement are the main reasons for some of the country's persistent environmental problems.

Pan also urged China's legislature to amend its 17-year-old environmental law to hold government officials accountable for pollution.