Venezuela has denied destroying two gold-mining dredges on Guyanese territory following a strong protest from Guyana's government.
Guyana says 36 Venezuelan soldiers used helicopters and Compostion-4 (C-4), a type of plastic explosive, to blow up the two dredging machines on Thursday.
It has summoned Venezuela's ambassador to explain the incident.
Venezuela denies using force and said the army was removing illegal miners inside its own territory.
The dredges were in a disputed border region that has seen a number of recent incidents.
Guyanese troops and police travelled to the border on Friday to investigate whether the incident took place on the Wenamu River between the two countries, or the Cuyuni River in Guyana, according to the Associated Press news agency.
Guyanese Foreign Minister Rudy Insally told the news agency AFP that his country was "very disturbed by this report because it affects our territorial sovereignty."
But Venezuela's ambassador to Guyana, Dario Morandy, told AFP that his country could provide co-ordinates to show the incident had occurred within Venezuelan borders.
The ambassador also accused illegal miners of polluting rivers with mercury and said Venezuela was protecting its natural resources.