Bolivia referendum: Voting ends on fourth term for Morales
People in Bolivia have voted in a referendum to decide whether President Evo Morales may stand for a fourth consecutive term of office.
Provisional results and exit polls are expected in the coming hours.
The country's first president of indigenous origin faces a tough challenge after 10 years in power.
He called a referendum to ratify constitutional amendments approved by parliament last year, saying he needed more time to complete social reforms.
The opposition says the change is undemocratic.
"On Sunday we will win big," Mr Morales said during the campaign. "The people will decide and there will be a lot to celebrate."
Burning ballot boxes
Polling stations began to close around 16:00 local time (20:00 GMT).
In the eastern province of Santa Cruz, angry voters set fire to ballot papers and ballot boxes after a delay to the opening of several polling stations.
Mr Morales, an indigenous Aymara and former coca leaf producer, took office in January 2006.
His first term in office would have run from 2006 to 2011.
But in 2009 he cut the term short, calling for a referendum on a new constitution and early elections.
Voters approved the new constitution and re-elected him by a landslide.
The 2009 constitution limits presidents and vice-president to two consecutive terms in office, which would have prevented Mr Morales from running again in 2014.
But the Constitutional Court said Mr Morales's first term should not be counted under the rule because it had not taken place under the new constitution.
His current term ends in 2020 but he will be able to run again in 2019 and serve until 2025 if Sunday's referendum is approved.
Despite a drop in the international price of oil and natural gas, the Bolivian economy has performed well in the past 10 years, growing on average 5% a year.
The government's socialist policies have also been successful in reducing extreme poverty.
But recent allegations that Mr Morales used his influence to favour a Chinese construction firm in Bolivia have damaged his approval ratings.
A former girlfriend of Mr Morales, Gabriela Zapata, holds an important position in the company, CAMC, which has secured more than $500m (£350m) in contracts with the Bolivian government
Mr Morales rejected the allegations and said he had nothing to hide. He ordered an investigation into how the contracts were awarded.