Clashes again erupted in La Paz between security forces and thousands of protesters demanding the nationalisation of the country’s energy sector and improved rights for indigenous people.

“The country is on the verge of a civil war,” Mr Mesa said in his second televised address in as many days. “By holding elections, we will avoid loss of human life. We will avoid violence that affects us all.”

He also criticised Congress for delaying its decision on his resignation until Thursday, stressing he wouldn’t change his mind.

His resignation could ultimately usher in new elections, raising the prospect of Bolivia becoming the seventh Latin American country to elect a leftist government opposed to US policies in the region.

President Mesa’s appeal came as anti-government demonstrators fought running battles with police, continuing the four-week campaign that’s paralysed the capital.

The demonstrators are mainly made up of Indian peasant farmers, miners and trades union members.

The government has raised taxes on oil and gas companies doing business in Bolivia in a bid to quell discontent, but protestors have vowed to continue until their goal is met.

Abel Mamani, a key protest leader, dismissed President Mesa’s resignation as “a tactic to demobilise” the protesters.

“Our demands are of national scope, and we will continue to press our demands until they are fulfilled,” he said.

Also at issue is the Washington-backed war on drugs. One popular opposition leader draws his support from farmers who grow coca leaf, the raw ingredient for cocaine.

The United States urged Bolivians to respect the country’s laws and constitution.

“We stand ready to assist if there is need for assistance,” said US State Department spokesman Sean McCormack.

The State Department also warned US citizens to defer travel to Bolivia and authorised the departure of US diplomats’ family members.