Hundreds of thousands of protesters marched through the streets of Bolivia's largest city, turning up heat on President Evo Morales as they voiced outrage over his government's response to wildfires that have razed broad swaths of the country's forests this year.

Protesters in the wealthy, industrial city of Santa Cruz brandished placards at the demonstration late on Friday calling for a "punishment vote" against Morales in the upcoming Oct. 20 presidential election.

Tightening polls show Morales, Latin America's longest-serving leftist leader, may be forced into a second-round runoff with his chief rival, Carlos Mesa, a business-friendly former president.

For weeks, opposition candidates and protesters have called on Morales to declare this year's surge in wildfires, which have already scorched an area larger than Costa Rica, a national disaster to help facilitate international aid. Morales' government has said a disaster declaration could invite foreign meddling in a sovereign issue, echoing concerns voiced by neighboring Brazil's far-right President Jair Bolsonaro, who has sparked a global outcry over his handling of fires in the Brazilian Amazon.