Guyana on Friday accused Venezuela's navy of detaining a US-operated research vessel in disputed waters off its coast, in a fresh territorial spat between the South American neighbors.

The Guyana Foreign Ministry said a Venezuelan navy ship had confronted the Teknik Perdana on Thursday as it explored off the coast of Essequibo, a region Venezuela claims is its own.

The ship, contracted to Texas-based Anadarko Petroleum Corporation, was ordered to sail to Margarita Island in Venezuela, the statement said.

"One point is clear and that is that the Teknik Perdana was in Guyana's waters when this incident took place," the foreign ministry statement said, demanding the immediate release of the ship and its crew.

"The Government of Guyana is of the firm belief that the actions taken by the Venezuelan navy vessel constitute a serious threat to the peace of this sub-region and the Government of Guyana therefore strongly condemns these actions," it added.

Contacted by AFP, the Venezuelan defense ministry declined to comment.

The Guyana statement said the Teknik Perdana had been conducting a multi-beam survey of the seafloor when it was stopped.

Venezuela and Guyana remain locked in territorial disputes concerning the Essequibo region, a wrangle that dates back to the 19th century.