The consuls of Peru and Colombia in Manaus, aware of the consequences of a possible confrontation, proposed to their governments the diversion of the expeditions, seeking that the Colombian expedition commanded by General Neira stop in Manaus, while the Peruvian, commanded of Commander Benavides, in Putumayo. However, due to lack of knowledge about these negotiations, the armed clash between the Peruvian and Colombian forces took place in La Pedrera between July 10 and 13. The Colombian troops established in La Pedrera had created a permanent camp, which included crops and a set of trenches. Most of the Colombian soldiers became ill with
malaria,
yellow fever or
leishmaniasis, which led to 11 becoming sick, 22 dying, and leaving 34 unfit for combat at the time of the confrontation. On July 10, the Peruvian commander Óscar Benavides demanded the withdrawal of the Colombian forces, the refusal caused the first confrontation between both parties. 111 Colombian soldiers from the trenches repelled the attack of four river gunboats with 100 men, and after two hours of combat, the breakdown of the river gunboat
América gave rise to Benavides' withdrawal. The next day, 23 Colombians managed to hold the position until the night. Thirty minutes before midnight, however, a new Peruvian attack was carried out which could not be successfully repelled by Gamboa. On July 12, the third and final day of the conflict, 43 Colombian soldiers fought successfully for most of the day, but General Gamboa passed out due to being ill while carrying a box of ammunition, being carried by his men. La Pedrera was consequently evicted and the Colombian troops were forced to withdraw. ==Aftermath==