Complex sentence: In a separate incident, he ordered the transfer of 15% of the Mexican military to the state of Guerrero to counter guerrilla groups operating there, and under Echeverría's secretaryship, the air force allegedly used napalm against rural communities in Guerrero.
Split into simpler sentences: In a separate incident, he ordered the transfer of 15% of the Mexican military to the state of Guerrero to counter guerrilla groups operating there. Under Echeverría's secretaryship, the air force allegedly used napalm against rural communities in Guerrero.