Colombia's leftist ELN rebel group said Tuesday it was willing to free an engineer they have held captive for more than a year, while calling for the Chilean company he works for to leave the country.

In a statement published on its web site, the ELN said it had decided to release Andres Montes on "humanitarian grounds," though it insisted the captive was "in good health."

Police in Colombia have arrested 17 people allegedly involved in an international cocaine-smuggling ring, authorities said Saturday.

Justice officials said the arrests in the northern districts of Magdalena, North Santander and Guajira followed a six-month investigation by the Area Intelligence Narcotics Division.

The Colombian government and the leftist guerrilla group FARC said Thursday they were extending their latest round of peace negotiations, signaling progress on a key issue in the year-old talks.

The sides agreed to talk until Monday "with the objective of advancing the discussion and building an agreement on the second point of the agenda," FARC representative Marcos Calarca said.

Colombia's FARC said Monday the U.S. State Department played a "decisive role" in the leftist guerrilla group's release of a US national held captive for four months.

Kevin Scott Sutay, a former U.S. Marine, was turned over Sunday to a delegation of the International Committee of the Red Cross, which handed him over to U.S. authorities.

Colombia's leftist FARC rebels have released a former U.S. Marine after holding him for four months, in a move promptly hailed by Washington on Sunday.

"We welcome the release today of Kevin Scott Sutay from captivity at the hands of the FARC," U.S. Secretary of State John Kerry said in a statement.

The FARC guerrilla group on Wednesday praised a proposal that calls for declaring an armistice before a peace agreement is reached in Colombia's near half-century-old conflict.

The proposal by conservative politician Alvaro Leyva came as negotiators for the rebels and the government of President Juan Manuel Santos began another round of peace talks in Havana, their 16th.

A new 21-story apartment building collapsed in the Colombian city of Medellin, leaving 11 workers missing in the rubble, authorities said Sunday.

The building had been evacuated after inspectors warned of a risk of collapse, but workers were inside trying to shore up the structure when it came down Saturday night, the mayor's office said.

Colombia's leftist guerrillas on Friday criticized President Juan Manuel Santos's "unfortunate" decision to order a military offensive amid peace talks.

Santos ordered the armed forces Wednesday to dismantle the FARC's southern and eastern units, with a priority on capturing or killing five guerrilla leaders, according to Colombian media.

A former senator who has frequently served as a mediator with the FARC said Thursday she will ask the rebel group to declare a unilateral ceasefire during Colombia's 2014 elections.

"We could move forward suggesting a unilateral ceasefire to the FARC, as they did during Christmas last year,... so that the elections can truly take place peacefully," former senator Piedad Cordoba told RCN radio.

Colombian rebels blamed a lack of progress in peace negotiations on the country's defense minister, whom they accused of trying to undermine the talks.

After 11 months of negotiations, the Bogota government and leftist fighters from the Revolutionary Armed Forces of Colombia have reached a deal on just one key issue -- agrarian reform -- with progress stalled on four other agenda items.