Quito - Ecuador's embattled president, Rafael Correa, said the government had "clear indications" a coup would be attempted when opposition protesters marched in the capital on Thursday.
"Unfortunately, we have clear indications that coup plotters intend to take Carondelet," Correa wrote on Twitter on Wednesday, referring to the country's seat of government in Quito.
The president has faced nearly a month of protests demanding his departure over his policies, including an initiative to increase inheritance taxes.
The coup claim and planned protests come just ahead of a visit from Pope Francis next week.
But opposition leaders denied any suggestion of a coup.
Lawmaker Andres Paez, a promoter of the protest, said it was "outrageous" to suggest demonstrators would stage a coup.
He called on marchers not to "yield to provocation."
The Catholic Church in Ecuador has tried to discourage protests ahead of the pope's visit.
Since early June, Correa has faced numerous protests against his government. He temporarily suspended legislative work ahead of the pope's visit.