WASHINGTON (Reuters) - The United States on Wednesday blacklisted four Colombian citizens and five Colombian companies for their links to accused drug traffickers, the Treasury Department said in a statement.

The blacklisted companies operate out of a single address in Medellin, in northwestern Colombia. The companies are ultimately owned or controlled by Juan Santiago Gallon Henao, who along with his brother Pedro David Gallon Henao was sanctioned by the Treasury Department in 2015 for being “long-time drug traffickers” and for their connections to La Oficina, a Colombian criminal group.

Three of the four Colombian nationals sanctioned on Wednesday - the brothers’ business partner and Juan Santiago Gallon’s ex-wife and 24-year-old daughter - worked on Juan Santiago’s behalf as managers and shareholders of the businesses, which were involved in family estate management, mining and coffee cultivation, the Treasury said.

Another person sanctioned was the brothers’ attorney, who the Treasury said was involved in their criminal activities.

“These new Treasury designations will further reduce the economic power of La Oficina’s longtime financiers by identifying and targeting front persons and companies working on their behalf,” said John Smith, director of the Office of Foreign Assets Control, the Treasury agency that implements sanctions.

The measures bar Americans from dealing with the people and companies and freezes any assets they might have in the United States.

The Gallon Henao family were well-known alleged cocaine traffickers during the 1990s who were accused of using their wealth to fund paramilitary gangs. Pedro David Gallon Henao and Juan Santiago Gallon Henao were investigated for their role in the 1994 killing of Colombian footballer Andres Escobar, while their other brother, Jose Guillermo Gallon Henao, was extradited to the United States.