Venezuelan oil shipments have slowed sharply after US forces seized a tanker carrying sanctioned crude, reports London's Sky News.

Special forces and the coastguard boarded the vessel Skipper about 70 miles offshore, saying it was transporting oil from Venezuela and Iran. The ship was loaded with 1.8 million barrels of Merey heavy crude. President Nicolas Maduro denounced the action as piracy, claiming Washington's real aim is regime change.

The United States has tightened sanctions, targeting six supertankers, shipping firms and three of Mr Maduro's nephews. Tanker movements in and out of Venezuela have nearly halted, with about 11 million barrels of oil and fuel now stuck in national waters, according to Reuters data.

The Skipper was the first Venezuelan tanker seized since sanctions began in 2019. US officials said the vessel used "spoofing" to hide its location. The raid coincided with the expiry of a court warrant authorising the seizure, signed by Magistrate Judge Zia Faruqui.

Despite the clampdown, Chevron remains exempt under US government approval to deal with state-run PDVS. The company exported two cargoes after the seizure and prepared two more on Friday. Venezuela had shipped 952,000 barrels per day in November, most bound for China, revenues crucial to Mr Maduro's rule.

The seizure followed a US naval build-up in the region, which has destroyed boats alleged to be smuggling drugs. However, no firm evidence has been provided. Most Western governments view Mr Maduro as a dictator who jails opponents and manipulates elections to stay in power.