The US Customs and Border Patrol (CBP) Friday issued a withhold release order against Chinese fishing company Dalian Ocean Fishing.

Withhold Release Orders are targeted bans on the import of products from a company or region based on the use of forced labor. Recently, CBP also banned the import of cotton and tomatoes from Xinjiang over similar claims. Unlike sanctions, withhold release orders are issued directly by CBP after an investigation into forced labor. Sanctions are typically created by executive order.

This effort marks the first time that the US has blocked the import of an entire fleet’s products, as opposed to those of a single ship. CBP alleges a widespread practice of forced labor on Dalian Ocean Fishing ships, across their 32 ship fleet. Dalian Ocean Fishing maintains fishing operations off the coasts of China, Indonesia and Senegal.

Forced labor has been described as a form of modern slavery. However, unlike slavery, forced labor does not require one person to have legal ownership of another. Rather, forced labor refers to work that is performed involuntarily and under threat of penalty, typically violence, according to the UN’s International Labor Organization(ILO). CBP alleges that it has identified all 11 of the ILO’s indications of forced labor on Dalian Ocean Fishing vessels.