Officials are now confirming that a small number of the advanced F-35 stealth fighter jets have arrived in Puerto Rico as part of an ever-growing buildup of military assets in the region aimed at striking drug cartels.

Two U.S. officials confirmed that a “handful” of F-35 jets are now in the U.S. territory. They spoke on condition of anonymity to freely discuss ongoing operations.

The confirmation comes amid U.S. plans to move 10 jets to the region and as online plane spotters noticed some jets making the move from U.S. bases over the weekend using tracking websites.

Video and photos of the planes in Puerto Rico have also made their way online.

The jets join a small flotilla of Navy ships, including several ships that are carrying more than 2,000 Marines, as well as maritime patrol aircraft that have been in the region for weeks.

AP Video shot by Alejandro Granadillo