( CNN ) -- At least seven people were killed in southwest Guatemala when security forces clashed with protesters blocking a highway , a hospital official said . More than 30 others were hospitalized with injuries , 15 of them in serious condition , Damaris Juarez , a spokeswoman at Jose Felipe Flores Hospital , said Thursday . Most of the victims suffered bullet wounds , she said , although the government says its forces were unarmed in the confrontation , which took place in the country 's Totonicapan department . Protesters from 48 local communities had gathered Thursday at a stretch of highway known as Cuatro Caminos to express their opposition to high energy prices , among other issues . The leader of the protests , Carmen Tacan , blamed security forces for the deaths and demanded an investigation , according to a government news release . Guatemalan President Otto Perez Molina ordered an investigation but suggested that the shooting originated from the protesters . `` We are willing to make available the weapons that they may have been carrying , although they -- the soldiers -- had no weapons , but were equipped with tear gas , '' Perez Molina said . `` We have information that it may have been the civilians who initiated the shooting and upon hearing this , the contingent of soldiers exited their vehicles to disperse and avoid harm . '' The president said he ordered police and military forces to retreat from the area where the protesters were . In addition to high energy costs , the protesters also oppose an educational reform that will increase the duration of studies needed for a teaching degree from three years to five years . CNN 's Nelson Quinones contributed to this report .
More than 100 others were injured , most with bullet wounds , a hospital reports . The protesters accuse security forces of opening fire . Yemen 's president says the protesters were not armed . The protesters were expressing opposition to high energy prices , educational reforms .