The US military has boarded a second oil tanker in the Indian Ocean, after tracking it from the Caribbean Sea where it was suspected of helping Venezuela avoid US sanctions.

The boarding of the Panamanian-flagged Veronica III is the second such US interception in the Indian Ocean in the past week. It comes amid a US crackdown on sanctioned oil exports from Venezuela.

"Distance does not protect you," the Pentagon said in a statement, alongside video and photos which appear to show the US raid.

At least seven oil tankers have been seized by the US since last year, as the Trump administration moves to control the supply of Venezuelan oil.

The Pentagon statement on Sunday defined the operation as "a right-of-visit, maritime interdiction and boarding". The statement did not say whether the US had seized the vessel, or allowed it to continue on its journey.