June 23 (Reuters) - The United States on Wednesday restricted exports to five Chinese companies that it said were implicated in Chinese human rights violations, including large producers of polysilicon for the solar panel industry. The companies added to the Commerce Department"s Entity List include Hoshine Silicon Industry Co (603260.SS), Xinjiang Daqo New Energy Co, a unit of Daqo New Energy Corp (DQ.N), Xinjiang East Hope Nonferrous Metals Co, a subsidiary of Shanghai-based manufacturing giant East Hope Group, Xinjiang GCL New Energy Material Co and Xinjiang Production and Construction Corps (XPCC) (XJPCCP.UL) At least some of the companies are major manufacturers of monocrystalline silicon and polysilicon that are used in solar panel production. The companies were listed over human rights violations and abuses of the Uyghurs and other Muslim minorities, according to a government filing on Wednesday. The department said the firms are accepting or utilizing forced labor. U.S. officials had suggested that the Biden administration was considering restrictions on Chinese solar producers in Xinjiang, where much of the global supply of polysilicon used in solar panels is sourced. "It is my understanding that the Biden administration is right now in the process of assessing whether or not that will be the target of sanctions," Biden"s climate envoy John Kerry told the U.S. House of Representatives in May, referring to solar products in Xinjiang. The XPCC was sent to Xinjiang in the 1950s to build farms and settlements. It remains powerful in the region"s energy and agriculture sectors, operating almost like a parallel state. read more Foreign governments and human rights activists say it has been a force in the crackdown and surveillance of Uyghurs in the region, running some detention camps. The U.S. Treasury Department last year sanctioned XPCC for "serious rights abuses against ethnic minorities." In March, the U.S. Treasury Department announced sanctions on two more Chinese officials in connection with serious human rights abuses in China"s Xinjiang region, where Washington says ethnic Muslims are the victims of genocide, including Wang Junzheng, secretary of the Party Committee of XPCC.