Aware of the situation, the American consul at Kingston sent word to the military that the Spanish were preparing to send a resupply convoy from that city to the southern coast.

To thwart these efforts, on 28 June President McKinley extended the blockade to include the southern coast of Cuba as well as Puerto Rico.

In order to enforce the blockade, a flotilla of gunboats and auxiliaries — including the USS Hist, Hornet, and Wompatuck—was sent to patrol the area.

While patrolling near the Niguero Bay, the small, 30 long tons (30 t) Spanish gunboat Centinela was sighted, and the Americans decided to engage her.

Starting to take damage and casualties, the Americans decided to withdraw, since their gunboats' armaments were not enough to destroy the rest of the Spanish squadron.