About a dozen tankers loaded with Venezuelan crude oil and fuel have left the country's waters in dark mode since the start of the year, according to documents seen by Reuters and industry sources including monitoring service TankerTrackers.com.

The movements suggest a potential breaking of ‍a strict blockade imposed by President Donald Trump before the dramatic capture of Venezuelan President Nicolas Maduro by U.S. troops in the early hours ⁠of Saturday morning. Trump said on Saturday that the oil embargo remained in full force after Maduro's extraction.

All the identified vessels are under sanctions and most of them are supertankers ​that typically carry Venezuelan crude to China, according to TankerTrackers.com and shipping documents from state-run Venezuelan oil company PDVSA.

Representatives of the White House, the U.S. State Department, PDVSA and Venezuela's oil ministry did not respond immediately ‍to requests for comment outside of business hours early on Monday.

A separate group of smaller ships, also ⁠under sanctions, left the country after discharging imports or completing domestic trips.

At least four of the departed tankers left Venezuelan waters on Saturday through a route north of Margarita island after briefly stopping near the country's maritime border, TankerTrackers.com said after identifying the vessels using satellite images.

A source with knowledge of ⁠the departure paperwork told Reuters that at ​least four supertankers had been ⁠cleared by Venezuelan authorities to leave in dark mode.

It was not immediately clear if the departures were in defiance of ‍the U.S. blockade. Though President Trump said that the oil embargo had not been lifted, he added that Venezuela's largest customers, ‌including China, would keep receiving oil.

PDVSA had accumulated a large inventory of floating storage since the U.S. blockade began last month, dragging the country's oil exports to a standstill. The company is ⁠reducing oil output ​and asked some joint ‍ventures to shut well clusters because of accumulated oil and residual fuel stocks both onshore and in vessels anchored near its ports.

Oil exports are Venezuela's main ‍source of revenue, which will be needed by an interim government led by Oil Minister and Vice President Delcy Rodriguez to finance spending and secure stability in the country.