WASHINGTON (AP) — U.S. forces on Saturday stopped a second merchant vessel off the coast of Venezuela in international waters, two American officials told The Associated Press.

The move comes days after President Donald Trump announced a “blockade” of all sanctioned oil tankers coming in and out of the South American country and follows the Dec. 10 seizure by American forces of an oil tanker off Venezuela’s coast.

The officials were not authorized to discuss publicly the ongoing military operation and spoke on condition of anonymity.