There have been clashes in Bolivia between security forces and protestors opposed to a controversial increase in water rates.

The unrest began when the security forces fired tear gas and rubber bullets to break up a march by thousands of demonstrators through the central city of Cochabamba.

More than thirty people were reported injured.

Dozens of protestors were arrested and the government announced it would declare a state of siege unless order is restored.

Local residents are angry over plans to increase water rates by twenty per cent in order to fund a project to improve the city's water system. On Thursday, the president, Hugo Banzer, expelled a junior partner in his coalition government for speaking out against the increase.

From the newsroom of the BBC World Service