The US Coast Guard is in active pursuit of another vessel in international waters near Venezuela, an official has told the BBC's US partner CBS News, as tensions in the region continue to escalate.

US authorities have already seized two oil tankers this month - one of them on Saturday. Sunday's pursuit relates to a sanctioned dark fleet vessel that is part of Venezuela's illegal sanctions evasion, according to a US official. It is flying a false flag and under a judicial seizure order.

Washington has accused Venezuela of using oil money to fund drug-related crime, while Venezuela has described the tanker seizures as theft and kidnapping.

US President Donald Trump last week ordered a blockade of sanctioned oil tankers entering and leaving the country. Venezuela, which has the world's largest proven oil reserves, has accused the Trump administration of trying to steal its resources.

Authorities have not yet confirmed the exact location and name of the tanker pursued on Sunday. As of last week, over 30 of the 80 ships in Venezuelan waters were under US sanctions.

Saturday's seizure involved a Panamanian-flagged tanker, which was boarded by a specialized tactical team. Although not officially listed as sanctioned, it was allegedly carrying sanctioned PDVSA oil. Venezuela has responded by stating that these acts will not go unpunished and plans to file a complaint with the UN Security Council.

Over the past weeks, the US has strengthened its military presence in the Caribbean and has conducted operations against alleged Venezuelan drug trafficking boats, resulting in significant casualties. However, the military actions have come under scrutiny in Congress due to a lack of public evidence linking the vessels to drug activity.

The Trump administration has accused Venezuelan President Nicolás Maduro of leading a terrorist organization called Cartel de los Soles, an allegation Maduro vehemently denies.