Clashes have broken out in the Peruvian capital, Lima, between security forces and protesters angry at the impeachment of President Martín Vizcarra.
Riot police were out in force to keep the demonstrators back, using tear gas and jets of water.
The police tried to keep hundreds of people away from the Congress building.
On Monday, Congress voted to impeach Mr Vizcarra over allegations he handed out government contracts in return for bribes.
The unrest occurred as the Speaker of Congress Manuel Merino was being sworn in as the country's interim president.
There are concerns of a growing political crisis as Peru faces a severe economic downturn brought on by the coronavirus pandemic.
Mr Vizcarra enjoys continued support among many voters for his reform attempts.
As an independent, he repeatedly clashed with Congress, and some of his supporters have labelled his ousting a coup.
Mr Vizcarra previously said he would accept the impeachment vote, not take any legal action, and leave the presidential palace. But on Tuesday, he questioned the "legality and legitimacy" of his removal.
"Legality is in question because the Constitutional Court has not yet ruled, and legitimacy is given by the people," he told reporters outside his home in Lima.
Mr Merino is expected to assume the presidency until July 2021 - when Mr Vizcarra's term was due to end.
Monday's move in Congress came after a previous attempt to oust the president. An earlier vote held on 18 September fell far short of gaining the necessary votes when only 32 lawmakers cast their ballot in favour of removing Mr Vizcarra.
Mr Vizcarra, 57, has previously denied allegations that he accepted bribes worth 2.3m soles ($640,000; £487,000) when he was governor of the southern Moquegua region.
He became president in March 2018 and had been embroiled in a bitter battle with Congress, which is dominated by rival parties, since he took office.
Last year, the president dissolved Congress, arguing that lawmakers were obstructing his anti-corruption agenda.
A new Congress was elected in January, but tension remains high between the legislative and the executive, with Mr Vizcarra accusing lawmakers of fostering "chaos and disorder".
Presidential elections are scheduled for April 2021, and Mr Vizcarra is banned by the constitution from running for a second term.