At least six people have died in Guatemala in clashes between security forces and protesters angry over electricity price rises, officials say.
At least 30 were also injured as thousands blocked parts of a motorway in Totonicapan, 170km (105 miles) west of the capital, on Thursday.
Government officials said unidentified people had opened fire on the demonstrators from the back of a lorry.
Local activists said police and soldiers had shot the protesters.
Reports said the shooting took place after soldiers were drafted in to help police who had been ordered to evict the protesters from the road.
At a news conference, Guatemalan President Otto Perez Molina denied that the military had been involved in the incident, saying he had been told that the truck from which the shots had been fired had civilian licence plates.
Interior Minister Mauricio Lopez Bonilla said that some of the injured had knife or machete wounds, and that another 13 had been beaten. Seven soldiers were reported to be among those injured during the clashes.
On Friday, grieving relatives hurled themselves on coffins as they passed through Totonicapan's central square, while others cried out for justice.
Thursday's protest was fuelled by anger at Mr Perez Molina, who has proposed constitutional reforms that he says will modernise Guatemala's economic and regulatory systems.
The reforms would set price caps on electricity but the protesters believe the caps are too high.