Two 12-year-old children were among the dead, according to Maria del Carmen Sajquim, spokesperson for Guatemala’s Western Regional Hospital.
Six people were injured, she added.
The injured people were transferred to the hospital and were believed to have suffered fractures, local firefighters said earlier on Twitter.
Witnesses at the scene said the venue for the event only had two exit doors.
First aid workers were helping injured people and ambulances were at the scene, images from Guatemala’s Red Cross showed on Twitter. Local media described the concert as an annual event marking independence day in the Central American country.