Colombian military chiefs have hailed the death of a legendary leftwing guerrilla leader as the “hardest blow” ever suffered by Farc, Latin America’s oldest rebel group.

The death of Manuel Marulanda was confirmed by a senior guerilla commander known as Timochenko in a video released on Sunday by television network Telesur. He said the 78-year-old founder of Farc had died of a heart attack “following a short illness”.