Brazilian President Luiz Inacio Lula da Silva has vowed to purge the country's police force and the army of U.S.-backed former president Jair Bolsonaro's sympathizers after security forces refused to respond properly to destructive riots in the capital by Bolsonaro's supporters.

Brasilia, January 13 (RHC)-- Brazilian President Luiz Inacio Lula da Silva has vowed to purge the country's police force and the army of U.S.-backed former president Jair Bolsonaro's sympathizers after security forces refused to respond properly to destructive riots in the capital by Bolsonaro's supporters.

Lula pledged to carry out the purge on Thursday, less than a week after thousands of the former far-right head of state's supporters forced their way into the country's Congress, Supreme Court, and the presidential palace in the absence of much resistance on the part of the security forces.

"There were a lot of people who were complicit in this among the military police.  There were many people from the armed forces who were complicit," Lula told journalists.  "I am convinced that the door to the palace was opened to allow these people in because I did not see that the door was broken," Lula added.

Riot police dispersed the crowd with teargas and arrested some 1,800 protesters only after Lula ordered the federal government to intervene.  Images shared across social media have, meanwhile, shown some police members taking selfies with the rioters and chatting with them in the buildup to the melee.

Lula has also lashed out at the army for refusing to clear out the two-month-old encampment of Bolsonaro's supporters outside its headquarters, where they have been calling for the army to overthrow Lula.

Commenting on Lula's planned purge, Presidential Chief of Staff Rui Costa said the government now faces the challenge of undertaking a "decontamination" of the security forces and holding those responsible accountable.  "We have several institutions that have been contaminated with Bolsonarista hatred by far-right coup-mongers," said Institutional Relations Minister Alexandre Padilha.

The Bolsonaro-allied fanatics refuse to accept his narrow defeat during October's presidential elections against 77-year-old Lula da Silva, also a former president.

Lula was sworn in on January 1st, unleashing a barrage of rebuke against Bolsonaro for, what he called, his predecessor's egregious mishandling of the country's affairs during his mandate.

Hours before the monumental swearing-in ceremony, which was attended by some 30,000 Brazilians, Lula blamed Bolsonaro for causing hunger to return to the country, despite his own presidential rule during which millions were lifted out of poverty.

He said he had received a ruined country, whose former government had depleted all resources and undermined human rights.

Lula da Silva also accused Bolsonaro's "negationist" administration of committing "genocide" by failing to respond properly to the COVID-19 pandemic that killed more than 680,000 Brazilians.