At least three prisoners were killed and six injured in an overnight revolt in an Ecuador prison, from which one of the country's most feared gang leaders escaped in January, authorities said Thursday.

It marked the latest prison violence in Guayaquil -- the port city that has become a dangerous hub for cocaine exports to neighboring countries.

The country's prison agency, SNAI, said in a statement that the three inmates died when a "clash" broke out with security forces Wednesday but that the facility "is 100 percent under control."

Ecuador President Daniel Noboa tweeted Wednesday that security forces had prevented a "possible escalation."

The riot was the first since Noboa took office in November.

AFP reporters heard gunshots and saw fires spreading inside the prison, one of four that make up a vast penitentiary complex in Guayaquil.

On Thursday, some 200 relatives of inmates burned tires to block traffic near the jail, protesting the alleged mistreatment of prisoners by the military -- which has been cited as a cause for the riot.

In January, the regional prison came into the spotlight after Adolfo "Fito" Macias, leader of one of the country's most powerful gangs, escaped from the jail. He remains on the loose.

After the escape, Noboa imposed a state of emergency -- which has been extended until April -- and declared war on the gangs that have sunk their claws into the country.

The narcos retaliated in a wave of violence that saw dozens of kidnappings and left around 20 people dead.

The government has deployed soldiers to retake control of the country's prisons, which had become the nerve center -- and battleground -- for gangs linked to Mexican and Colombian cartels.

Since 2021, more than 460 inmates have been killed in gang wars behind bars.

Once considered a bastion of peace in Latin America, Ecuador has been plunged into crisis by the rapid spread of transnational cartels that use its ports to ship drugs to the United States and Europe.

Deputy security minister Lyonel Calderon said a recent uptick in violence was part of an effort to "destabilize" the country ahead of a referendum on April 21 on whether to take tougher measures against crime.

The measures include the ability to deploy the military to back up police outside of a state of emergency, allowing the extradition of Ecuadorans involved in organized crime, and increasing sentences for terrorism and drug trafficking.