Guyana says the Venezuelan navy has entered its territorial waters and detained a US-operated ship.
Caracas has said the ship was operating illegally in Venezuelan waters.
The Venezuelan foreign ministry responded shortly after, issuing a statement demanding an official explanation from the Guyanan authorities.
The vessel - the Teknik Perdana - was surveying the seafloor on Thursday when it was approached by a Venezuelan navy vessel and forced to sail to Venezuela's Margarita Island. At least five US citizens are on board, the company said.
"One point is clear: the Teknik Perdana was in Guyana's waters when this incident took place," said the Guyanan foreign ministry in a statement.
The US state department said it was aware of reports that five US citizens were among crew members detained by Venezuelan authorities aboard the ship.
Guyana's government said Friday that Venezuela's navy has detained a ship operated by a U.S. oil company in waters disputed by the neighboring South American countries.
The ship was conducting a seismic survey under contract for Anadarko Petroleum Corp. on Thursday when it was stopped by a Venezuelan navy vessel.
The Guyana ministry said. "It was then clear that the vessel and its crew were not only being escorted out of Guyana's waters, but were under arrest. These actions by the Venezuelan naval vessel are unprecedented in Guyana Venezuela relations."
When asked about the incident at a news conference in Caracas,the Venezuelan minister stated, "We will jealously defend our country and our sovereignty," .
The minister said that Guyana and Venezuela have been in discussions over oil exploration in the area but he declined to discuss the status of those talks.
Guyana said that the vessel was merely collecting seismic data and that there was "ample time" to discuss any differences over the region with Venezuela since the actual exploration work had not yet started.