Ecuador has declared a state of emergency after an anti-corruption presidential candidate was shot and killed at a political rally.

The assassination of Fernando Villavicencio in the capital city Quito happened on Wednesday, less than two weeks before a special presidential election.

He was not a frontrunner, but his killing, which President Guillermo Lasso suggested could be linked to organised crime, furthered a crisis that has already claimed thousands of lives and underscored the deep challenge that the country’s next leader will face.

Mr Lasso declared three days of national mourning and a state of emergency that involves additional military personnel deployed throughout the country.

“Given the loss of a democrat and a fighter, the elections are not suspended; on the contrary, they have to be held, and democracy has to be strengthened,” Mr Lasso said on Thursday.

In his final speech before he was killed, Mr Villavicencio, 59, promised a roaring crowd that he would root out corruption and lock up the country’s “thieves”.

The attorney general’s office of Ecuador said one suspect died in custody from wounds sustained in a firefight after the politician’s assassination. Various operations carried out in different sectors of Quito resulted in six arrests.

Mr Villavicencio had reported receiving multiple death threats, including from affiliates of Mexico’s Sinaloa cartel, one of a slew of international organised 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,” Mr Villavicencio said in a statement before his death, naming detained crime boss Jose Adolfo Macias by his alias “Fito”.

Mr Villavicencio, one of eight candidates running for president, was the candidate of 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, Mr Lasso declared a state of emergency covering two provinces and the country’s prison system in an effort to stem the violence.

Former vice president Otto Sonnenholzner, who also is seeking the presidency, said at a news conference following the killing: “We are dying, drowning in a sea of tears and we do not deserve to live like this. We demand that you do something.”

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

Mr Lasso said “the murderers” threw a grenade into the street to cover their flight, but it did not explode. Police later destroyed the grenade with a controlled explosion, he added.

Mr Zuquilanda said the candidate had received at least three death threats before the shooting and reported them to authorities, resulting in one detention. The campaign adviser 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.”

Mr Villavicencio was one of the country’s most critical voices against corruption, especially during the 2007-2017 government of former president Rafael Correa.

He was an independent journalist who investigated corruption in previous governments before entering politics as an anti-corruption campaigner.

Mr 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 Mr Correa, and fled to indigenous territory in Ecuador, later receiving asylum in neighbouring Peru.

Mr Lasso, a conservative former banker, was elected in 2021 on a business-friendly platform and clashed from the start with the left-leaning majority coalition in the National Assembly.

A snap election was called after Mr Lasso dissolved the National Assembly by decree in May, in a move to avoid being impeached over allegations that he failed to intervene to end a faulty contract between the state-owned oil transport company and a private tanker company.

Ecuador’s constitution includes a provision that allows the president to disband the assembly during a political crisis, but then requires new elections for both the assembly and the presidency.

Diana Atamaint, the president of the National Electoral Council, said the election date of August 20 was “unalterable” due to constitutional and legal mandates, as well as electoral activities that have already been approved by the council.

The country has faced a series of political upheavals in recent years.

Authorities said that at least nine others were injured in the shooting, including officers and a congressional candidate, in what they described as a “terrorist act”.

The killing was met with an outcry by other candidates who demanded action, with presidential frontrunner Luisa Gonzalez of the Citizen Revolution party saying “when they touch one of us, they touch all of us”.

Mr Villavicencio was married and is survived by five children.