The flight comes as Washington carries out a military campaign against alleged drug smugglers in the region, deploying naval and air forces it says are aimed at curbing trafficking but which have sparked fears in Caracas that regime change is the goal.

Data from tracking website Flightradar24 showed the two bombers flying parallel to the Venezuelan coast, then circling northeast of Caracas before heading back along the coast and turning north and flying further out to sea.

It is at least the fourth time that US military aircraft have flown near Venezuela since mid-October: B-52s have done so on one previous occasion, and B-1B bombers on two others.

The United States has also ordered the USS Gerald R. Ford carrier strike group to Latin America, has deployed F-35 stealth warplanes to Puerto Rico and currently has six US Navy ships in the Caribbean as part of what it calls counter-narcotics efforts.

Washington's forces have carried out strikes on at least 17 alleged drug-smuggling vessels -- 16 boats and a semi-submersible -- since early September, killing at least 67 people, according to US figures.

But the United States has yet to release evidence that the vessels it has targeted were used to smuggle drugs or posed a threat to the country.

Regional tensions have flared as a result of the campaign and the accompanying military buildup, with Venezuela accusing Washington of plotting to overthrow President Nicolas Maduro.