A Colombian army Black Hawk helicopter landed in a minefield in a rural area of Teorama municipality in Norte de Santander province, and four of the soldiers on board were killed in the resulting explosion, military officials said Monday.According to reports from the soldiers on board the transport helicopter, six of whom were wounded, the explosives at the landing site were placed and detonated by the terrorist group FARC.The helicopter, belonging to the army's 33rd Mobile Brigade, was carrying 15 soldiers, local media reported.Operating in that area bordering on Venezuela are guerrillas of the FARC, the National Liberation Army (ELN), and the Popular Liberation Army (EPL). EFE