Venezuelan authorities captured a US spy targeting two oil refineries on the north Caribbean coast, claimed President Nicolas Maduro on Friday.

The country has been struck by a severe gasoline shortage amid ongoing political turmoil and US-imposed sanctions tied to Maduro's controversial 2018 election win.

The spy was allegedly "a marine who was serving as at CIA bases in Iraq" and who was captured with "heavy weapons" and "large amounts of cash," said Maduro.

The arrest took place on Thursday. The man was interrogated about his activities around the Amuay and Cardon refineries in Falcon state.

Authorities on Wednesday "discovered and dismantled" a "plan to cause an explosion" at a third refinery — El Palito, the closest to Caracas and located in Carabobo state.

Maduro blamed the US for the incident, saying: "the gringo empire wants revenge against Venezuela." He added: "It wants to prevent Venezuela from producing all petroleum products, gasoline."

The Venezuelan president urged the nation's oil workers to be on alert for more attacks.

Read more: Maduro orders EU envoy to leave Venezuela over sanctions

Oil scarcity

The petroleum industry was once the cornerstone of Venezuela's economy but critics claim that decades of rule under a succession of leaders have left the oil infrastructure near ruin.

Tight US sanctions imposed in 2019 to pressure Maduro to step down following his re-election in 2018 have also blocked the country from importing and producing crude oil.

Relations between the US and Venezuela's Maduro-led government have increasingly soured: last month two former US soldiers, Luke Alexander Denman and Airan Berry were sentenced to 20 years in prison in Venezuela on charges including terrorism, after a failed bid to invade the Caribbean country last May.

The Trump administration has denied involvement in the botched attack.

Read more: Opinion: Venezuela's opposition is falling apart

kmm/rc (AFP, AP)