The Trump administration said Wednesday that it is blocking shipments by the Chinese biotech company BGI Group and its affiliates, alleging ties to forced labor in China's far-west ethnic region of Xinjiang .

Starting Thursday, U.S. Customs and Border Protection will bar goods by BGI Group, a major biotech company known for its genetic sequencing technologies, as well as BGI Genomics and MGI Tech. The Department of Homeland Security said the companies are either sourcing materials from Xinjiang or working with the regional government to “recruit, transport, transfer, harbor, or receive forced labor” of members of persecuted ethnic groups in Xinjiang, including Uyghurs.

Adding the companies to a trade blacklist comes as biotechnology is emerging as another front in the economic and tech competition between the U.S. and China. The Treasury Department last week proposed new restrictions on U.S.…