BOGOTA, Nov 18 (Reuters) - Seven Colombian soldiers were killed by landmines and four guerrillas died in a subsequent gun battle over control of a long-time rebel stronghold near the center of the country, the army said on Sunday. A soldier tripped a landmine that set off a chain of explosions in Tolima province late on Saturday. Those who survived the blasts fired on members of Colombia's biggest rebel force, the FARC, which was born in Tolima in 1964. Thousands are killed every year in this war involving Marxist rebels and other militias funded by Colombia's multibillion-dollar cocaine trade. Nearly 600 members of Colombia's state security forces were killed in action last year. About three Colombians per day are maimed by landmines, many of them children from poor farming communities who step on the devices on their way to school. (Reporting by Hugh Bronstein; Editing by Bill Trott)
