Bolivian police clash with energy protesters

Bolivian anti-riot police used water canon and tear gas to drive back protesters demanding the nationalization of the country's natural gas and oil industry.

Police broke up miners who detonated dynamite blasting caps near the central square where there is the presidential palace and Congress building.

Another demonstration by street vendors tried to force their way past police and into the same Plaza des Armas, before being pushed back by police.

The Bolivian army appealed for calm before the new opposition rallies started, warning it would not allow protests that went outside the constitution.

Three large protest rallies calling for the nationalization of the natural gas and oil industry set out from different parts of the capital, heading for the Plaza des Armas.

Recent demonstrations in La Paz have ended in violence with security forces clashing with protesters demanding the country earn more from its valuable natural gas reserves.

As tensions have mounted, two oil-rich regions of the South American nation, Santa Cruz and Tarija, have called for greater autonomy and have called referendums for August 12 to back their claims.

The army, which supports President Carlos Mesa, said groups' demands must be made "through dialogue and consultation".

"Any decision that damages these principles, no matter how legitimate it is, cannot be accepted by the armed forces," said a military statement.

Troops and police were on duty in key parts of La Paz for the new demonstrations.

The scenes were reminiscent of disturbances just 19 months ago when demonstrations toppled President Gonzalo Sanchez de Lozada.

One rally started at El Alto, a suburb of the capital, whose participants chanted for oil interests to be nationalized without compensation. Bolivian storekeepers held a separate march, forcing the closure of nearly all small shops in La Paz.

Hundreds of peasant coca growers and other farmers, led by radical union leader Evo Morales, made up the third demonstration, which marched 200 kilometers (120 miles) to La Paz to demand that foreign companies pay bigger royalties on gas extraction.

Protesters forced out of the main square rallied in nearby San Francisco square, where workers, miners, teachers, street vendors and members of neighborhood groups demanded a constitutional assembly.

The Bolivian Congress voted last Tuesday to toughen an energy law, giving the state a greater stake in the natural gas industry.

The opposition groups say the law does not go far enough, but foreign oil companies who operate in Bolivia -- including ExxonMobil, Total, Petrobras, British Gas and Repsol -- say the legislation is tantamount to confiscation of their installations.

Bolivia, a nation of nine million people, has an estimated 48.7 trillion cubic meters of natural gas, the second-highest reserves in South America after Venezuela.