Chinese authorities are scrambling to deal with two more toxic spills polluting the country's rivers.
A string of spills has raised concerns about water quality
Officials said water supplies were safe despite the spills, which hit rivers in central and eastern China.
The new alerts came as China was still struggling to deal with two earlier major toxic spills which left millions of people without drinking water.
Correspondents say the spills have focused attention on how polluted China's rivers have become.
In one of the two new cases, a botched environmental clean-up resulted in cadmium polluting a 100km stretch of the Xiangjiang river in central Hunan province.
The other accident occurred in eastern Shandong, when a pipe broke, dumping six tons of diesel into a tributary of the Yellow river.
In both cases, the authorities are trying to neutralise the spills with chemicals and say water supplies for residents remain safe.
But one of the BBC's Beijing correspondents says they are is an embarrassing reminder of just how badly polluted Chinese waterways are becoming.
It has also been announced that the clean-up of the Songhua river, which carried toxic benzene from north-east China into Russia, will cost $3bn and take five years.
Following an official cover-up of that incident, new emergency response guidelines have been drawn up, requiring local authorities to report such disasters promptly.
But the fact that such toxic spillages seem now to be occurring on a regular basis shows the price China is paying for its economic boom.