Colombian President Juan Manuel Santos ratified a Dec. 9 decision by the Inspector General's Office to remove this capital's leftist mayor, Gustavo Petro, for alleged mismanagement.

The president's decision to oust the former guerrilla came a day after the Inter-American Commission on Human Rights instructed Colombia to desist from enforcing the IG office's order, which also bars Petro from public office for 15 years.

"I must proceed in accordance with the constitution and the laws," Santos told Colombians in a televised address Wednesday night.

At the president's side was Foreign Minister Maria Angela Holguin, who said the instruction from the human rights commission - a body of the Organization of American States - constituted "interference" in Colombia's domestic affairs.

Santos named Labor Minister Rafael Pardo as acting mayor of Bogota pending a special election to choose a permanent successor to Petro, who has spent the last three months battling the IG ruling in Colombia's court.

Soon after the president's speech, Petro, 53, spoke to supporters from the balcony of city hall.

"I was not born in a generation that has been accustomed to kneel before the Colombian oligarchy," said the erstwhile mayor, who spent two years in prison in the 1980s for his activities with the now-defunct M-19 rebel group.

He vowed to lead an uprising of Colombian citizens that will "force the oligarchy to convene a constituent (assembly) to make peace."

"Voting is useless in Colombia," Petro said.

Trash piled up in Bogota for several days in December 2012 after Petro decided to shift responsibility for waste management from four private firms to the municipal water company.

The mayor harmed "the principle of freedom of enterprise" and put at risk "the environment and human health of the residents of Bogota," Colombian Inspector General Alejandro Ordoñez said in his Dec. 9 decision ordering Petro's ouster.

The action of the IG's office has been roundly criticized in Colombia and abroad, with even Petro's political foes accusing Ordoñez, an outspoken right-winger, of having gone too far.

What remains to be seen is the effect the Petro case will have on the Santos administration's peace process with the Revolutionary Armed Forces of Colombia, or FARC, the Andean nation's largest insurgency.

In previous comments on the affair, the FARC said Ordoñez was providing a "lesson ... about what democracy means to the oligarchy."

The latest round of peace talks between the Santos government and the FARC began Thursday in Havana. EFE