In Arequipa, the second largest city in Peru, anti-government demonstrators barricaded roads and besieged the international airport on Monday as deadly turmoil escalated.

Former Marxist President Pedro Castillo’s supporters flocked to the streets in protest of his impeachment and detention.

In reaction to the protests, his successor and former deputy, Dina Boluarte, advocated shifting general elections forward by two years to April 2024.

Mr. Castillo referred to Ms. Boluarte’s ideas as “dirty tricks.”

At least seven people have been killed in skirmishes with security forces since protests for Mr. Castillo’s impeachment began on Wednesday.

Just hours before his impeachment vote, he was accused of corruption and jailed for attempting to dissolve the opposition-controlled Congress.

In a handwritten letter he tweeted on Monday, he referred to Ms. Boluarte as a “usurper” and claimed he was “kidnapped” and humiliated.

Mr. Castillo’s supporters assert that Ms. Boluarte was not chosen by the people. They are asking that new elections be held in Peru, with some also calling for the dissolution of Congress and the release of Mr. Castillo.

On Monday, protesters blocked highways and set fire to vehicles, while an estimated 2,000 demonstrators stormed the airport in the southern city of Arequipa, obstructing the runway and forcing several hours of flight cancellations. Finally, police dispersed the crowd using tear gas.

During a televised speech to the nation earlier in the day, Ms. Boluarte, the first woman to lead Peru, announced that she would propose a measure to Congress to hold elections in April 2024 instead of April 2026.

Ms. Boluarte stated that she would also propose constitutional revisions to establish “a more efficient, transparent, and participatory system of government,” but she did not elaborate on these reforms.

This action constitutes a U-turn. Ms. Boluarte, who was sworn in as president on Wednesday, stated upon assuming office that she would complete the remaining five years of Mr. Castillo’s tenure.

A judge ordered Mr. Castillo to be held in pre-trial custody for seven days while an inquiry determines whether he should be charged with rebellion.

How Ms. Boluarte handles the protests is considered a crucial test for her president and her ability to remain in office until April 2024.

Decades of political instability have plagued Peru, with the legislature and executive nearly continuously at odds.

Ms. Boluarte is the sixth president in as many years to assume office.