A view of a polluted river in China, November 2005. Two top leaders of an environmental protection bureau in central China have been sacked over a massive arsenic spill which poisoned a major river, state media has said.[AFP]

Beijing - Two top leaders of an environmental protection bureau in central China have been sacked over a massive arsenic spill which poisoned a major river, Xinhua news agency has said.

Chen Lin, director of the Linxiang City Environmental Protection Bureau, and Liu Yushu, a deputy director, were sacked for failing to inspect two chemical plants responsible for the September 8 spill along the Xinqiang river in Hunan province, Xinhua said Tuesday.

Investigators said the two plants had severely violated environmental laws when dumping arsenide, a highly toxic arsenic compound, into the river.

The pollution forced the local government to suspend drinking water supplies to 80,000 people for four days. No casualties were reported.

A chronic intake of arsenide could cause liver and kidney damage or lung and skin cancer.

The local environmental protection bureau also violated rules when issuing pollutant discharge permits and were lax in their supervision, the report said.

Top managers at the two chemical plants were arrested shortly after the spill and the plants were shut down.

The two companies had discharged waste water with arsenide content of more than 1,000 times the national standard, previous reports said.

The Chinese government has vowed to crackdown on ecological destruction as it acknowledges the need to adjust the nation's growth model after 25 years of rapid economic growth.