BOGOTA (Reuters) - Colombian armed forces killed Marxist insurgent commander Walter Patricio Arizala in an operation aimed at ending his attacks on civilians after he kidnapped and shot dead three Ecuadorean media workers earlier this year, President Ivan Duque said on Friday.

Arizala, known by his war alias Guacho, was killed in a police and military operation near the border with Ecuador, Duque said in a televised statement.

Arizala was a member of the Oliver Sinisterra unit - a faction of former rebels of the Revolutionary Armed Forces of Colombia (FARC) that refused to adhere to a 2016 peace agreement. The government had deployed more than 3,000 members of the armed forces to search for Arizala “dead or alive.”

“The message is clear, we won’t take a step back in the defense of legality, life, honor and the property of Colombians,” Duque said. “Many Colombian communities will sleep well because one of the most horrendous criminals the country has known is dead.”

Arizala, who was 29, was accused of drug trafficking, extortion and homicide.

He killed two Ecuadorean journalists and their driver after taking them hostage on March 26 as they reported on assignment for the Quito-based El Comercio newspaper on the border between Ecuador and Colombia.

“I told the Ecuadorean people that the crime of the three Ecuadoreans would not end in impunity,” said Duque.

A proof-of-life photograph released shortly after the Ecuadoreans’ kidnapping showed them chained and padlocked by their necks. Arizala later shot them in the head.

The media crew was reporting on violence in the Esmeraldas region of the border when they were snatched by Arizala’s gang.

Colombia and Ecuador had both offered $100,000 each for information leading to Arizala’s capture.

More than a thousand FARC fighters refused to demobilize under the peace accord with former President Juan Manuel Santos and continued cocaine trafficking across the nation. There are now almost 1,800 members of the dissident ranks in 30 units nationwide.

Those operating in Colombia’s southern jungles have attacked Ecuadorean security forces along the border.

The FARC, which battled for more than a half century before demobilizing, attacked military targets and civilian towns but generally allowed journalists to work freely, unless they went against the rebels’ interests.