At least nine people died and 20 others were injured early Thursday in a stampede after an independence day concert in Guatemala, rescue workers said.

"The Guatemalan Red Cross and volunteer firefighters stabilized more than 20 injured people and nine people died at the scene" in the western city of Quetzaltenango, the relief agency said on Twitter.

Local press reported that the victims were crushed as thousands of people tried to leave an open-air esplanade at the end of a concert during the traditional "Xelafer" festival, about 200 kilometers (120 miles) west of Guatemala City.

People attending the event "didn't even realize people were being crushed because it was already dark," resident Monica Gonzalez told AFP.

"They started fighting with each other, pushing each other and falling down and that's when it all happened."

Another witness, Luis Carrion, told AFP he saw people being pushed and falling to the floor before they were trampled by people leaving the venue.

"More than anyone else, those who organized the event are responsible for this."

Red Cross spokesperson Andres Lemus said the injured were taken to local hospitals.

He added that the dead had suffered "multiple traumas."

Public ministry spokesperson Moises Ortiz told AFP that prosecutors had begun gathering information for an investigation, while the national forensic sciences institute had activated four morgues to carry out autopsies.

The Guatemalan government has yet to comment on the tragedy.

President Alejandro Giammattei was taking part in a procession in the capital in front of the National Palace Museum.

It was the first time in three years that Guatemala celebrated its independence from Spain after the previous two years' festivities were called off due to the coronavirus pandemic.

Guatemala gained independence from former colonial power Spain on 15 September 1821.