Quito, Ecuador. An Ecuadorian presidential candidate known for speaking up against cartels and corruption was shot and killed Wednesday at a political rally in the capital, amid a startling wave of gang-driven violence in the South American country.

President Guillermo Lasso confirmed the assassination of Fernando Villavicencio and suggested organized crime was behind his slaying, less than two weeks before the Aug. 20 presidential election.

“I assure you that this crime will not go unpunished,” Lasso said in a statement. “Organized crime has gone too far, but they will feel the full weight of the law.”

Ecuador’s attorney general’s office said that one suspect died in custody from wounds sustained in a firefight after the killing, and police detained six suspects following raids in Quito.

In his final speech before he was killed, Villavicencio promised a roaring crowd that he would root out corruption and lock up the country’s “thieves.”

Prior to the shooting, Villavicencio said he had received multiple death threats, including from affiliates of Mexico's Sinaloa Cartel, one of a slew of international organized crime groups that now operate in Ecuador. He said his campaign represented a threat to such groups.

“Here I am showing my face. I'm not scared of them,” Villavicencio said in a statement, naming detained crime boss José Adolfo Macías by his alias “Fito.”

Villavicencio was one of eight candidates, though not the frontrunner. The politician, 59, was the candidate for the Build Ecuador Movement.

As drug traffickers have begun to use the country’s coastal ports, Ecuadorians have reeled from violence not seen for decades. The sounds of gunfire ring in many major cities as rival gangs battle for control, and gangs have recruited children. Just last month, the mayor of the port city of Manta was shot and killed. On July 26, Lasso declared a state of emergency covering two provinces and the country's prison system in an effort to stem the violence.

Videos of the rally on social media appear to show Villavicencio walking out of the event surrounded by guards. The video then shows the candidate getting into a white pickup truck before gunshots are heard, followed by screams and commotion around the truck. This sequence of events was confirmed to The Associated Press by Patricio Zuquilanda, Villavicencio’s campaign adviser.

Zuquilanda said the candidate had received at least three death threats before the shooting, which he had reported to authorities, resulting in one detention. He called on international authorities to take action against the violence, attributing it to rising violence and drug trafficking.

“The Ecuadorian people are crying and Ecuador is mortally wounded,” he said. “Politics cannot lead to the death of any member of society.”

Villavicencio was one of the country's most critical voices against corruption, especially during the 2007-2017 government of President Rafael Correa.

He was also an independent journalist who investigated corruption in previous governments, later entering politics as an anti-graft campaigner.

Villavicencio filed many judicial complaints against high-ranking members of the Correa government, including against the ex-president himself. He was sentenced to 18 months in prison for defamation over his criticisms of Correa, and fled to indigenous territory in Ecuador, later receiving asylum in neighboring Peru.

Villavicencio was married and is survived by five children.