The Spanish garrison at Igueriben was cut off but could communicate with the fort at Annual via heliograph. From the heliograph, Silvestre learned that the men at Igueriben had no water and been reduced to drinking the juice from tomato cans, then vinegar and ink, and finally their own urine. With the dehydrated men of Igueriben in desperate condition, a relief force from Annual was sent down on July 19 but was ambushed and destroyed, with 152 Spanish killed. On July 21, Silvestre sent down another relief force of 3000 men, which was likewise ambushed and defeated.