HAVANA — The rebels have blown up oil pipelines and blasted police stations in Colombia with homemade bombs. They take over highways, shutting down parts of the country for days. They have killed soldiers in ambushes — and kept others alive as hostages of their guerrilla movement.

For years, the rebel chain of command has run through Israel Ramírez Pineda, one of the five guerrilla leaders who run the last major insurgent group in Colombia, the National Liberation Army.

From an old basement in an empty Havana hotel, only a short distance from where he now lives, Mr. Ramírez is demanding that the government negotiate with him, counting off the latest captives his rebel group has seized: four soldiers, three police officers and two military contractors.

“A Colombian liberal leader once said a half-century ago, ‘Better to use your mouth than use your bullet,’” Mr. Ramírez told The New York Times this week in Havana, saying that he ultimately wanted to talk with the government, rather than take hostages. He added that the hostages could be released in the coming days as a gesture of good will.