Personnel from a U.S. warship boarded a Venezuelan tuna boat with nine fishermen while it was sailing in Venezuelan waters, Venezuela’s foreign minister said on Saturday, underlining strained relations with the United States.

The White House did not immediately respond to a request for comment.

Tensions between the two nations escalated after U.S. President Donald Trump in August ordered the deployment of warships in the Caribbean, off the coast of the South American country, citing the fight against Latin American drug cartels.

While reading a statement on Saturday, Foreign Minister Yván Gil told journalists the Venezuelan tuna boat was “illegally and hostilely boarded by a United States Navy destroyer” and 18 armed personnel who remained on the vessel for eight hours, preventing communication and the fishermen’s normal activities. They were then released under escort by the Venezuelan navy.