Three members of Colombia's Marxist-inspired ELN rebel group were killed this weekend in an army strike after the government launched peace negotiations with no ceasefire in effect, the armed forces said Monday.

Army troops backed by the air force and national police carried out the raid in Litoral de San Juan, a remote area of the northern department of Choco, killing three members of the local National Liberation Army front and injuring several others including a 13-year-old girl fighter, the army said.

The girl will be turned over to state social services, it said.

The government hopes the talks will bring the ELN into a broader peace process alongside the biggest rebel force, the Revolutionary Armed Forces of Colombia (FARC).

The parties are trying to end what is seen as the last major armed confrontation in the West, which has killed 260,000 people since it broke out in 1964.

After more than three years of peace talks in the Cuban capital Havana, the government and FARC say they are close to signing a deal.

Hostilities on the ground have fallen dramatically, with the FARC observing a unilateral ceasefire since July.

But a number of thorny issues still stand in the way of a final accord.

So far, the two sides have reached deals on four of their six agenda items: justice for victims, land reform, a political role for ex-rebels and fighting the drug trafficking that fuels the conflict.

The unresolved issues are disarmament and how to ratify a final accord.